United's 4-1 victory over Sparta Prague has provided the Reds with another platform to grasp some elusive momentum in their season.
Sir Alex Ferguson has warned his players not to throw this opportunity away.
Too many times this season - in particular, the 6-2 victory over Fenerbahce and the 2-0 win against Arsenal - United have failed to capitalise on positive results.
"We keep saying that all the time," said Sir Alex after watching his side put four past the Czechs. "No matter what team I pick, we all deserve to see better than we did on Saturday [against Portsmouth].
"Tonight [Wednesday] is really confirming the ability of the team, that is all.
"Sparta showed an attacking enterprise which surprised us because we didn't see anything like that in the first game against them.
"In their previous games in the Champions League they played nothing like that. So you have to congratulate them on their performance.
"What it did lead to was a game that was open. Within the first 20 minutes it could have been 4-4.
"But we got the goals that mattered - particularly the third goal, which was the deciding goal really. They [Sparta Prague] had some momentum at that time. Ruud's third killed them off."
Lyon clinched qualification to the knockout stages in Group D's other fixture, scoring two injury-time goals to seal a 4-2 win over Fenerbahce.
United, on eight points, trail the French side by two points at the top of the group. Lyon are United's next European opponents at Old Trafford later this month.
"We would probably have preferred Lyon to get a draw on Wednesday night," said Ferguson. "They are safe now and have qualified. We don't want to be going to Fenerbahce needing a draw so we need to win our match against Lyon."
The Reds would seal their passage into the knockout rounds with a win over the group leaders.
"We'll be going for the win like we normally do" said Ferguson positively. "Getting through to the next stage is our first priority."
United now focus on the Manchester Derby at Old Trafford on Sunday. Sir Alex, already without van Nistelrooy who serves out the final game of his three-match suspension, may be without flu virus-victim Mikael Silvestre.
"There is a bit of a virus going about at the moment. Gary Neville had a bit at the weekend, which is why we took him off against Portsmouth. Carlos [Queiroz] has a bit of a virus as well. Mikael has come down with it. Hopefully it's nothing other than that."
Report by Ben Hibbs, at Old Trafford.
Sir Alex Ferguson has warned his players not to throw this opportunity away.
Too many times this season - in particular, the 6-2 victory over Fenerbahce and the 2-0 win against Arsenal - United have failed to capitalise on positive results.
"We keep saying that all the time," said Sir Alex after watching his side put four past the Czechs. "No matter what team I pick, we all deserve to see better than we did on Saturday [against Portsmouth].
"Tonight [Wednesday] is really confirming the ability of the team, that is all.
"Sparta showed an attacking enterprise which surprised us because we didn't see anything like that in the first game against them.
"In their previous games in the Champions League they played nothing like that. So you have to congratulate them on their performance.
"What it did lead to was a game that was open. Within the first 20 minutes it could have been 4-4.
"But we got the goals that mattered - particularly the third goal, which was the deciding goal really. They [Sparta Prague] had some momentum at that time. Ruud's third killed them off."
Lyon clinched qualification to the knockout stages in Group D's other fixture, scoring two injury-time goals to seal a 4-2 win over Fenerbahce.
United, on eight points, trail the French side by two points at the top of the group. Lyon are United's next European opponents at Old Trafford later this month.
"We would probably have preferred Lyon to get a draw on Wednesday night," said Ferguson. "They are safe now and have qualified. We don't want to be going to Fenerbahce needing a draw so we need to win our match against Lyon."
The Reds would seal their passage into the knockout rounds with a win over the group leaders.
"We'll be going for the win like we normally do" said Ferguson positively. "Getting through to the next stage is our first priority."
United now focus on the Manchester Derby at Old Trafford on Sunday. Sir Alex, already without van Nistelrooy who serves out the final game of his three-match suspension, may be without flu virus-victim Mikael Silvestre.
"There is a bit of a virus going about at the moment. Gary Neville had a bit at the weekend, which is why we took him off against Portsmouth. Carlos [Queiroz] has a bit of a virus as well. Mikael has come down with it. Hopefully it's nothing other than that."
Report by Ben Hibbs, at Old Trafford.