American teenager Coco Gauff was the first big-name casualty at Wimbledon after losing a high-quality match against a resurgent Sofia Kenin.

Seventh seed Gauff lost 6-4 2-6 6-4 in the first round to qualifier Kenin, who has dropped down the rankings since winning the 2020 Australian Open.

Kenin, who has been hampered by injuries and upheaval in her coaching set-up, said she felt "super proud".

Top seed Iga Swiatek laid down a marker with a 6-1 6-3 win over Zhu Lin.

When the Wimbledon draw was made on Friday, Gauff being handed one of the trickiest draws possible - against a former Grand Slam champion looking to reignite her career - instantly caught the eye as a potential shock.

Gauff knew the danger posed by 24-year-old Kenin and her wariness proved correct as she lost in the first round at the All England Club for the first time.

The 19-year-old burst on to the scene at Wimbledon in 2019 when, as a 15-year-old phenomenon, she came through qualifying before shocking five-time champion Venus Williams on her way to the last 16.

That success led to bold predictions of how many Grand Slams she would go on to win and, even though lifting one of the sport's biggest prizes has not yet materialised, the world number seven was expected to go far at a major tournament where she has previously done well.

However, she was outpowered by an inspired Kenin who showed why she was one of the WTA Tour's rising stars only a few years ago.

"I knew it was going to be a tough first round for me. I tried my best, but it wasn't enough," said Gauff.

"I think I have a lot to work on if I want to improve from this."

Former world number four Kenin targeted Gauff's weaker forehand and maintained an aggressive approach throughout with clean ball-striking.

"Obviously this means a lot. I feel like this year has been not necessarily lows, but I feel like it's a comeback year for me," said 128th-ranked Kenin, who also reached the Roland Garros final in 2020.

"I feel like I started off the year well, I was playing well. I had a good feeling that this year would be a good year for me."

Swiatek feeling 'less rusty' at Wimbledon

Poland's Swiatek, 22, is one of the favourites for the women's title but has never managed to go beyond the fourth round on the grass in SW19.

However, the French Open and US Open champion began her quest to add another major on another surface in style.

In the build-up to Wimbledon, Swiatek talked about her intention to become an all-court player and believed she is now better prepared to challenge at the All England Club than she has been in previous years.

"Last year was a little bit more tricky because I felt rusty mentally, in terms of the focus tennis-wise, because I didn't play any matches on grass," said Swiatek, who won the junior title at Wimbledon in 2018.

"I think this year is much more comfortable for me."

The evidence from her opening match against Chinese world number 34 Zhu certainly pointed to that.

Since lifting her fourth major title on the Roland Garros clay last month, Swiatek has been spending time on the trickier grass surface and reached the semi-finals of a warm-up tournament in Germany last week.

Swiatek withdrew from her last-four match on Friday through illness, but showed no signs of any after-effects as she started strongly.

After fighting off a break point in the first game, Swiatek moved a double break up at 5-0 and, after Zhu finally got on the board after 31 minutes to a huge ovation, sealed the opener with her third set point.

The second set was not as straightforward for the world number one. The pair exchanged breaks for 2-2 but Swiatek broke again for 3-2 shortly before they were forced off court by rain.

When they returned, Swiatek quickly wrapped up victory by breaking again in the ninth game and finishing off with another stylish winner.

Pegula through after being fired up by line call

Swiatek is joined in the second round by American fourth seed Jessica Pegula and French fifth seed Caroline Garcia.

Pegula, 29, beat fellow American Lauren Davis 6-2 6-7 (8-10) 6-3, while Garcia won 6-4 6-3 against another American player, Katie Volynets.

Like Swiatek, Pegula is a top player whose success has come away from the grass courts, having never gone past the third round at Wimbledon.

In a tight battle with 46th-ranked Davis where both players struggled with the windy conditions, she was unable to convert three match points in the second-set tie-break and had to dig deep in the decider.

Falling a break down early on, Pegula instantly put the set back on serve - after being fired up by a line-call ruling from the umpire which she thought was "significantly out".

Pegula fought back from 30-0 to break and took Davis' serve again for 5-3 before closing out the match.

"I was able to find a little moment there where I was able to get myself going a little bit, just for the fact I was a little annoyed with that point, that circumstance," she said.

What else has happened on day one?

Belarusian 19th seed Victoria Azarenka, a two-time Grand Slam champion and former Wimbledon semi-finalist, progressed with a 6-4 5-7 6-4 success over China's Yue Yuan, while Russian 11th seed Daria Kasatkina won 6-1 6-4 American Caroline Dolehide.

Russian 12th seed Veronika Kudermetova reached the second round for only the second time, beating Estonian veteran Kaia Kanepi, 38, in a 7-6 (7-4) 6-4 victory.

Along with Gauff, three other seeds fell on the opening day of the Championships.

Russian Liudmila Samsonova, seeded 15th, was beaten 7-6 (7-1) 7-6 (7-4) by Romania's Ana Bogdan, before China's 24th seed Zheng Qinwen lost to Czech Katerina Siniakova and Egyptian 31st seed Mayar Sherif went out to Spain's Rebeka Masarova.