Tennis has a new pantomime villain and his name is Daniil Medvedev.

The Russian troll teased the crowd on Louis Armstrong Stadium as he was booed before and after his four-set win over German qualifier Dominik Koepfer.

"Guys, continue to give me this energy - you're the best, you're the best," said the 23-year-old after reaching the US Open quarter-finals on Sunday.

His will play 2016 champion Stan Wawrinka next after defending champion Novak Djokovic pulled out of his fourth-round match against the Swiss 23rd seed because of injury.

The fifth seed was fined $9,000 (£7,400) for a visible obscenity and unsportsmanlike conduct in his third-round victory against Feliciano Lopez on Friday.

He was booed when he entered the arena on Sunday before recovering from a set and a break down to win 3-6 6-3 6-2 7-6 (7-2).

Medvedev then relished the boos that rang out during his on-court interview and encouraged the crowd to raise the volume by waving his arms in the air.

He said: "I was losing 6-3 2-0. I was painful in my abductor before the match, and thought I was not going to play. I was painful in my shoulder. I took as much painkillers as I could and you guys, being against me, gave me so much energy to win. Thank you."

Later, in his news conference, Medvedev said he had "acted like an idiot".

But will that stop him doing the same if he wins his quarter-final?