LONDON, United Kingdom (AFP) — Novak Djokovic launched his bid for an eighth Wimbledon title on Monday with a 40th successive win on Center Court while American stars Coco Gauff and Venus Williams were knocked out.

The 36-year-old Djokovic, who has won the past four titles at the All England Club, defeated 68th-ranked Pedro Cachin of Argentina, 6-3, 6-3, 7-6 (7/4) on the tournament's showpiece court, where he has not lost since 2013.

Djokovic even found time to help ground staff dry out the world's most famous lawn after the surface became too slippery following a downpour.

The roof was closed but play did not resume for about 90 minutes, much to the frustration of the fans.

"When I come out, I usually come out with rackets, not towels," said Djokovic, who described the court as "the holy grail, the temple of tennis."

He added: "The conditions were not great under the roof, it was still slippery. I think it was definitely frustrating for the crowd waiting for us."

The Serbian, bidding to match Roger Federer's men's record of eight Wimbledon titles, goes on to face Australia's Jordan Thompson for a place in the third round.

World No. 2 Djokovic has already pocketed the Australian Open and French Open this year.

Winning a men's-record 23rd major in Paris put him just one behind Margaret Court's all-time singles mark of 24.

He is also half way to pulling off the first calendar Grand Slam since Rod Laver in 1969.

In the day's biggest shock, seventh-ranked Gauff slumped to a 6-4, 4-6, 6-2 defeat to fellow American Sofia Kenin, who came through qualifying.

Kenin, now ranked 128th in the world, was Australian Open champion and French Open runner-up in 2020 before injury and loss of form saw her career slip into a downward spiral.

"This means a lot — I had to go through qualification," she said.