Manager Graham Potter heaped praise on man-of-the-match Dan James after Swansea City beat Brentford 4-1 on Sunday to qualify for the quarter-finals of the FA Cup.
James scored Swansea's second goal after a long solo run, was fouled by Ezri Konza for the red card that reduced Brentford to 10 men at 2-1 and had a hand in George Byers' 90th-minute goal.
"He's got lots to work on but he had an end-product today and I thought he was sensational," said Potter of the 21-year-old, who was close to joining Leeds on the final day of the January transfer window.
"The ability to sprint repeatedly, it's as high a level as you're going to see."
James came in for some rough treatment from Brentford defenders and Potter said: "Dan's courage is incredible, to not only have the ability to do it, but to ride the challenges. He's a top player."
Potter also praised James' reaction to the breakdown of the move to Leeds.
"You forget that these things happen in transfer windows where clubs don't agree a price," said Potter.
"You can see why on that performance, the numbers are too low, that's the reality in my opinion.
"Once that happens he just gets on with being a footballer, he's been incredible for us and we're looking forward to working with him for the future."
Meanwhile, Brentford manager Thomas Frank revealed he had apologised to Swansea striker Oli McBurnie for the incident that saw the Danish manager booked by referee Stuart Atwell.
"I think it was a situation where I thought it was a 50:50 situation for who won the throw-in," said Frank.
"I thought we were a little bit too open and I still wanted to win the game so I thought I need to be first to the ball.
"I think I had the first contact and then McBurnie ran into me and gave me a dead leg, but it was my own fault. I said sorry to him afterwards and we've talked about it."