NEW YORK: Novak Djokovic moved within four matches of completing the first men's singles calendar-year Grand Slam in 52 years on Saturday (Sunday in Manila) while top-ranked Ashleigh Barty was eliminated from the US Open by a stunning fightback from American Shelby Rogers.
World number one Djokovic defeated Kei Nishikori 6-7 (4), 6-3, 6-3, 6-2, taking his 17th consecutive victory over the Japanese star and improving to 18-2 in their overall rivalry.
"I was very pleased with the focus," Djokovic said. "Maybe at some points I wasn't my best, but I was determined and focused and that made the difference."
With a fourth career US Open trophy, Djokovic would complete the first men's singles sweep of major titles in the same year since Rod Laver in 1969.
Reigning Wimbledon champion Barty won 11 of 14 games after dropping the first set, only for Rogers to capture five of the last six games for a shocking 6-2, 1-6, 7-6 (5) triumph.
"I didn't want to leave," Rogers said. "I just said make balls, try to stay in this match, it can't get any worse, you've lost to her every time."
Rogers had dropped all five prior meetings with Barty but would not be denied, breaking the Aussie as she served for the match in the eighth and 10th games as the crowd went wild at Arthur Ashe Stadium.
"I was just trying to stay in the point longer than Ash," Rogers said. "I was happy with myself for sort of problem solving. I'm just so excited to be moving on to the next round."
Rogers will next face 150th-ranked British qualifier Emma Raducanu, an 18-year-old who routed Spain's Sara Sorribes Tormo 6-0, 6-1 in 70 minutes.
Djokovic, meanwhile, marched toward a 21st career Grand Slam title, which would break the deadlock for the men's record he shares with Rafael Nadal and Roger Federer, both absent with injuries.
The 34-year-old Serbian star advanced to a fourth-round matchup on Monday against 99th-ranked US wildcard Jenson Brooksby.
"He was playing pretty solid," Nishikori said. "I couldn't break the wall. Very unfortunate I lost."
Djokovic, who had 52 unforced errors and 45 winners, dropped the last three points of the first-set tie-breaker, the last on a Nishikori service winner.
But Djokovic broke early in each set from there to seize command. In the fourth he grabbed a 3-2 lead and never dropped another game.
Tokyo Olympic champion Alexander Zverev defeated 184th-ranked Jack Sock 3-6, 6-2, 6-3, 2-1 when the American retired with a right thigh injury.
Fourth seed Zverev, the 2020 US Open runner-up, joined qualifiers Oscar Otte and Peter Gojowczyk as the first German trio in the US Open fourth round since 1994 and any Slam last 16 since Wimbledon in 1997.