RUUD van Nistelrooy admits his 100-goal achievement would have been tainted if United had lost against Everton.
Only Denis Law has reached the century mark quicker than the Dutchman - the Scot reached his 100 in April 1965 in 111 games; Ruud's landmark arrived at Goodison in his 131st match.
But the feat was almost ruined as the Reds blew a three-goal lead and almost threw away three championship points.
"Scoring 100 goals is great but it is all about winning the matches," the striker said.
"I scored the winner to make it 99 against Southampton and this week I scored again to make it 100 and then got the winner. That was the important thing.
"We had chances to score more in the first half. We created loads of chances - I had two more chances and Louis Saha had one apart from the ones we scored. But to score three in one half is good.
"You miss some and you score some and that is part of the game. However, it could have been four or five in the first half.
"I didn't expect their comeback to happen. In the first half we were dominant, created loads of chances and were the best team. In the second half they managed to turn it around which was disappointing for us.
"It was a relief when we got the fourth. When you are 3-0 up at half time if you only draw that is a big disappointment.
"But it does say something about our character that we were still able to win it even after that."
Skipper Roy Keane was also displeased about the way Everton were allowed back into the game and warned that United's title and Champions League ambitions will suffer if they continue to defend so poorly. It is a worry but we've managed to get away with it against Southampton and Everton," said Keane. "But against the top opposition in the Premiership or in Europe we certainly won't.
"You have to look at the bigger picture rather than two wins we've achieved in the last week and the fact is we can't keep giving goals away.
"We were fortunate against Southampton and were a little bit in the second half against Everton, but eventually you are going to come unstuck.
"It is a team thing and we must look at each other. I wouldn't be too critical of the defence.
"We were beaten at set pieces and on those set pieces the whole team is back there.
"At half time we said let's not give them encouragement because their fans were getting behind them and you sensed they had a good team spirit.
"We didn't want to encourage them but we went and did the opposite. We let them score within three or four minutes and they got stronger and stronger.
"I'd like to know what they took at half time! In the second half they looked a completely different team.
"In football you just never know and you saw it happen during the week with City at Tottenham and that's why we were disappointed only to be 3-0 up at half time.
"It could have been four or five and we are probably the only team around who'd be disappointed being 3-0 up at half time.
"Looking at it positively it showed great character from our players.
"To throw away a three-goal lead a lot of teams would have expected us to be happy with a point. But we kept in there."
Ruud van Nistelrooy's late goal gave Manchester United a 4-3 win at Everton after the hosts had battled back from three goals down.
Everton had been mauled in the first half by two goals from Louis Saha and van Nistelrooy's 100th United goal. But a second- half recovery saw them level with goals from Dave Unsworth, Kevin Kilbane and a John O'Shea own goal.
But United pulled themselves together and grabbed a crucial victory with a last-ditch van Nistelrooy header.
United led in the 11th minute when Saha latched on to Mikael Silvestre's long ball and lashed a shot past Nigel Martyn from 15 yards.
Van Nistelrooy had earlier missed a great chance when Paul Scholes' effort came off the post and the Dutchman ballooned the rebound over. But he made no mistake in the 24th minute with a fierce shot from the edge of the six-yard box.
And five minutes later, Saha got his second when he picked up Scholes' pass and he flashed a shot across Martyn and into the far corner.
Everton's best efforts of the first half came from Duncan Ferguson, who fired just wide and Lee Carsley, whose low near-post shot was collected by Tim Howard.
But Saha wasted the chance of a hat-trick on 36 minutes when he was all alone again as a Scholes pass reached him - but this time the Frenchman took aim and lashed the ball over the top.
Everton needed a quick response and they got just that when Unsworth powered home a header from Kilbane's corner. And they grabbed a second, again from a corner, when
Naysmith's effort swirled into the box, Ferguson and O'Shea went for it, and the ball looked to flick off the Irishman for an own goal.
The force was with Everton now and they drew level in the 75th minute when Thomas Gravesen's cross was met by Kilbane who rose above Silvestre to head powerfully past Howard.
But United had the last laugh when Ronaldo's cross from the right was met by van Nistelrooy at the far post and he powered a header home.
Louis Saha may have finished top of the strops but the Frenchman's public demand to join Manchester United earned appreciation inside the Old Trafford dressing room.
When the transfer window closed last night, the major focus of attention was on the way Saha, Scott Parker and Jermain Defoe levered their way out of clubs who did not want to sell them after receiving big-money offers to go elsewhere.
Saha was the most outspoken of all and told Fulham he would eventually let his contract wind down and leave for nothing if he was not allowed to join United.
While his comments may have brought widespread disapproval from the wider football world, new striker partner Ruud van Nistelrooy admitted they went down well with the Red Devils.
'Louis showed a lot of guts to leave Fulham,' the Dutchman told MUTV. 'It can't have been easy because Fulham had been good for him but he wanted to come to Manchester United and everyone could see that.
'All the fans appreciated it and all the players did as well.'
Sir Alex Ferguson believes the pair can rekindle memories of the 1999 Treble-winning efforts of Andy Cole and Dwight Yorke and new partnership could not have had a better start as both found the net in Saturday's 3-2 win over Southampton.
Van Nistelrooy can see elements of Yorke in Saha's play and revealed there has been an instant bond between them.
'Right from the first couple of training sessions I felt we were going to do well together,' he said.
'From what I have seen of Louis so far, he reminds me of Yorke. Like Dwight, Louis is strong in his upper body.
'He has great strength, turns sharply and is difficult for defences to contain.
'The encouraging aspect is that we don't do the same things, which is important at the start of a new partnership.
'When you have different movements and different qualities, it means you can change things and I feel we are going to be a lot more dangerous now.
'Saturday didn't feel like the first time we had played together. Louis brings a new dimension and once he settles in and get used to playing for United he will only get better.'
Louis Saha scored on his debut for Manchester United as the champions beat Southampton 3-2 at Old Trafford yesterday to return to the top of the English Premier League, but it was a controversial goal by Ruud van Nistelrooy that sealed the victory.
Arsenal, a point behind United in second, takes on Manchester City today, while Chelsea, six points further back in third, is in action away to Blackburn.
Saha, playing his first match for United since joining from Fulham, put the team ahead with a deflected free-kick after 17 minutes and Paul Scholes made it 2-0, only for Southampton to hit back through two goals from Kevin Phillips, either side of half-time.
But it was the winner, a deflected strike from Van Nistelrooy on the hour mark, that caused the controversy. As a free-kick from the right was sent over, the Dutchman was in an offside position. However, under the new guidelines for referees, a player is deemed not to be interfering with play unless he touches the ball.
The free-kick was partially cleared but when United bundled it back into the penalty box, Van Nistelrooy was there to knock it home. "He was offside," Southampton manager Gordon Strachan said. "I don't care about clauses ABC and D, all they do is cover the backsides of inadequate people.
The battle for fourth place intensified as Charlton, Liverpool and Newcastle all failed to win.
Charlton fell behind early at home to Bolton but looked on course for a good result when it equalized soon after, but a late winner from Kevin Nolan sealed a 2-1 win for the visitors.
Liverpool drew 0-0 at home with Everton in an action-packed 197th Merseyside derby riddled with outstanding chances and superb goalkeeping at both ends.
Newcastle seemed on course for all three points at St. Andrews thanks to Gary Speed's excellent 37th-minute shot but a last-minute equalizer by Stern John earned Birmingham a 1-1 draw.
Leeds remains bottom after going down 3-0 at home to Middlesbrough while Portsmouth and Wolverhampton Wanderers drew 0-0 in another relegation tussle at Fratton Park.
Fulham won 2-1 to hand Tottenham its first defeat of the year, while Aston Villa scored five goals in 20 second-half minutes to thrash Leicester City 5-0 away.
Ruud van Nistelrooy has signed a new contract with Manchester United that will keep the Dutch striker at Old Trafford until June 2008, the English Premiership champions said.
Van Nistelrooy, 27, told the club's official website: "I am delighted to commit my future to the club. I have grown very fond of Manchester United, the fans are amazing.
"I have had some great moments here but I want to continue to give the club my best, and I am looking forward to new challenges on the pitch," added the prolific forward who has scored 98 goals for the club since joining them in July 2001.
United manager Sir Alex Ferguson said: "We are delighted to get Ruuds signature on a new contract. It shows the ambition of the club to keep the best. Ruud has broken every record since he has been here.
"His improvement and continual commitment to the club is an asset. Ruud has proved to be a fantastic signing and his contract extension is great news for the club and the fans."
Van Nistelrooy, whose previous contract expired in 2005, joined United in a 19 millions pounds (34m dollars) move from Dutch giants PSV Eindhoven in 2001 after a broken leg delayed his original transfer.
His first season saw him net 36 goals in all competitions while in the Premiership he set a record by scoring in eight successive matches.
He is also United's joint leading scorer in European competitions, his tally of 28 goals in 30 matches equalling the record of forward Denis Law in three fewer games than it took the Scot to set his mark in the 1960s.