What you need to know:
- Rashford came on as a sub and plundered in a hat-trick.
- Mason Greenwood opened the scoring for Manchester United in the first half.
- Anthony Martial scored the other goal from the spot after Rashford won the penalty kick.
- Manchester United host bitter rivals Arsenal on Sunday in the English Premier League
Manchester, United Kingdom
Super sub Marcus Rashford scored a clinical second-half hat-trick as Manchester United ripped German league leaders RB Leipzig apart on Wednesday to seize control of their Champions League group.
Mason Greenwood looked like grabbing the headlines with his first-half strike but Rashford came off the bench to remind Ole Gunnar Solskjaer that he is the main man at Old Trafford.
He is only the second United player to score a hat-trick as a substitute after Solskjaer performed the feat against Nottingham Forest in 1999.
United, who endured a rocky start to their season, now have six points from two games after building on their impressive opening win against Paris Saint-Germain.
Rashford and Bruno Fernandes were surprisingly left on the bench as United went in search of their first home win of the season.
They took the lead midway through the first half when Greenwood, 19, received a through ball from Paul Pogba and stroked the ball across Peter Gulacsi and into the far corner for his first Champions League goal.
The home side were put under pressure by Julian Nagelsmann's team but substitute Rashford struck three times after coming on in the 63rd minute to put the result beyond doubt.
Anthony Martial also got in on the act, scoring a penalty on an outstanding night for the three-time European champions, who are now three points clear at the top of Group H.
"I think the manager wanted me to up the tempo," said Rashford.
"That for us means going forward. There was definitely spaces there. We got Bruno and Paul (Pogba) on the ball. We looked dangerous throughout and that we could score every time we went forward.
"It was a real team performance. The ones who started did well and the substitutes did well too. We can't ask for much more than that in terms of the attitude and the intent to go and kill the game off. It worked in our favour."
Greenwood, who last month was sent home in disgrace by England for breaking coronavirus protocols, started up front alongside Martial.
Leipzig started brightly, pinning the home side back but United soon settled.
They broke the deadlock when Pogba drove forward from midfield and fed Greenwood, who had timed his run into the box perfectly and hit his shot with unerring accuracy.
United had a nervous wait as VAR looked at a potential off-side but the goal was allowed to stand.
Leipzig came back strongly, pinning United back for long spells of the rest of the first half.
United goalkeeper David de Gea produced a sharp save to keep out a Ibrahima Konate effort at the back post.
The visitors, now with substitutes Marcel Sabitzer and Alexander Sorloth on the pitch, were playing with urgency but created few clear-cut chances as United kept their shape.
Solskjaer threw on Rashford, Fernandes and Scott McTominay to change the dynamics and reaped the rewards.
Fernandes sent a superb first-time ball through to Rashford, who raced through and slotted past Gulasci in the 74th minute.
The linesman had raised his flag for offside but VAR checked the decision, ruling that the forward started his run in his own half and awarded the goal.
Rashford rifled home again four minutes later to make the score 3-0 but then unselfishly allowed Martial to take the penalty after the Frenchman was brought down in the box.
But the England man completed his hat-trick in added time to cap a devastating display.