Top seed Novak Djokovic has been starved of competitive action at the US Open but on Sunday the world number one feasted on unseeded Briton Kyle Edmund in a 6-2 6-1 6-4 romp that put him into the quarter-finals.

Djokovic had a second-round walkover as Czech Jiri Vesely withdrew due to injury, and was leading 4-2 in his third-round match when Russian Mikhail Youzhny retired with a leg ailment, making it six days since his last full match.

The Serb kept himself busy on the practice courts but was happy to cut loose against an actual opponent, making 21-year-old Edmund the target of his arsenal of rifled groundstrokes, angled volleys, pinpoint passing shots, lobs and drop shots.

“Feels great to play a match,” Djokovic said in an on-court interview.

“I haven’t played much tennis.

“Baseline shots, both forehand and backhand, were working very well. Think I was most pleased with that.”

After two lopsided sets that Djokovic totally controlled, Edmund made the third set competitive, holding for 4-4 before the Serb closed out the set to end the match.

Djokovic’s victory put him into the last eight against ninth-seeded Frenchman Jo-Wilfried Tsonga, a 6-3 6-3 6-7 6-2 winner against American 26th seed Jack Sock.

Meanwhile, Rafa Nadal said he was sad to have squandered an opportunity to do something special at the US Open with his fourth-round loss at Flushing Meadows, but happy with his effort and prospects going forward this season.

“I fight until the end,” Nadal said about his 6-1 2-6 6-4 3-6 7-6 loss to 22-year-old Frenchman Lucas Pouille late Sunday.

“There were things I could do better. I had the right attitude. I fought right up to the last ball.

“But I need something else, I need something more that was not there today. I am going to keep working to try to find it.”

Nadal came back from more than two months of inaction due to a wrist injury that forced him out of the French Open and Wimbledon to compete last month at the Rio Olympics and won gold in doubles with Marc Lopez, and reached the singles semi-finals.

While he reports continued improvement in his left wrist, the 30-year-old Spaniard knows he still has a way to go.

“Is true that I don’t have lot of matches on my shoulders for the last three, four months, but even like this I lost an opportunity,” he said.

“I lost an opportunity to have a very good event here in the US... I am sad for that.”

Yesterday’s results: Del Potro bt Thiem 6-3 3-2 (Thiem retired); ­Wawrinka bt Marchenko 6-4 6-1 6-7 6-3.