Marcus Rashford revealed the secret of his wonder free-kick that booked Manchester United's quarter-final place was the lighter League Cup footballs.

Premier League games are played with Nike balls, but Carabao Cup games use Mitre footballs.

Rashford's stunning winner gave United a 2-1 lead against Chelsea, but he played down the effort.

Marcus Rashford hit a brilliant free-kick to win Manchester United's game against Chelsea

Chelsea goalkeeper Willy Caballero could only watch the free-kick fly into his net late on

'To be honest, it was the balls,' Rashford admitted. 'When we were training with them and we were shooting there was this up and down motion and they can go anywhere.

'Thankfully, today it went in the top corner.'

Having missed his second penalty of the season against Norwich at the weekend, Rashford stepped up to put United ahead from the spot in the first-half.

'You always step forward to take it and when the moment comes it is just about trying to be relaxed,' the England star added.

'Thankfully, today I was. It made the game a little bit easier for us but the second goal was the one that killed the game.

Rashford added: 'We have been in a tough place. We are still getting through that phase and the only way to do it is to fight your way through it.

'The main focus for us is just improvement and development because we are definitely going places. We have done a lot of good work.

'The start of the season wasn't exactly what we expected but we have got to get through it and get back to winning games.'