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 racquets, 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."

Grand Slam                   

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 number two 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 qualifyng.

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 qualies (qualification)," she said. "I battled out there. I am super proud of myself.

An emotional Gauff admitted she "had a lot to work on".

There was no fairytale for five-time champion Venus Williams, the 43-year-old American who made her debut at the tournament in 1997.

Williams, playing the singles event for the 24th time, was defeated 6-4, 6-3 by fellow wild card Elina Svitolina of Ukraine, a semi-finalist in 2019.

Williams took a nasty tumble early in the first set on Centre Court, hurting her right knee, which was already heavily strapped.

She required two visits by the trainer before her challenge fizzled out under the weight of 33 unforced errors.

'Killed by the grass'                  

"I was literally killing it, then I got killed by the grass," said Williams.

Seventh-seeded Andrey Rublev of Russia was the first men's winner of the day, beating Australia's Max Purcell 6-3, 7-5, 6-4.

Twelve months ago, all Russian and Belarusian players were banned by Wimbledon in response to the invasion of Ukraine.

"I think obviously there were better options -- not just to ban," said Rublev, who next faces compatriot Aslan Karatsev.

"Because in the end, there was no difference. They did only worse to themselves."

Fellow Russians Daria Kasatkina and Veronika Kudermetova, as well as two-time major winner Victoria Azarenka of Belarus, were also first day winners.

World number one Iga Swiatek racked up the first five games on her way to sweeping past China's Zhu Lin.

Reigning US Open and French Open champion Swiatek came through 6-1, 6-3 against her 34th-ranked opponent.

"I feel confident and did a good job of adjusting to grass," said the 22-year-old Pole, who has yet to get past the last 16 at Wimbledon. 

Security tight                   

Also making the next round were men's fourth seed Casper Ruud and eighth-seeded Jannik Sinner.

This year's tournament is being played under tightened security over fears that climate activists could disrupt matches following high-profile protests at other sporting events.

Three protesters from Just Stop Oil ran onto the ground during the second Ashes Test at Lord's last week, sprinkling the group's trademark orange powder.

"Of course we've taken account of what we've seen elsewhere so security has been uplifted in various places around the grounds," said All England Club chief executive Sally Bolton.

The extra security measures dampened the spirits of cold and wet fans lining up in Wimbledon's famous queue.

One fan tweeted he had been waiting for five hours, blasting the delay as "shambolic".