Serena Williams suffered a first-round loss in her first singles match in nearly a year, headlining Tuesday's action at Wimbledon.

Harmony Tan came through with a dramatic win over the unseeded American, quickly ending Williams' hopes of winning a 24th Grand Slam singles title.

Day 2 at the All England Club also featured Roland Garros winners Iga Swiatek and Rafael Nadal as they continued their winning streaks with first-round victories. There were also several upsets as Felix Auger-Aliassime and Belinda Bencic were eliminated.

Here is a full roundup of the latest results from London.

Notable Results

Men's Singles

No. 2 Rafael Nadal d. Francisco Cerundolo 6-4, 6-3, 3-6, 6-4

No. 4 Stefanos Tsitsipas d. Alexander Ritschard 7-6 (1), 6-3, 5-7, 6-4

Maxime Cressy d. No. 6 Felix Auger-Aliassime 6-7 (5), 6-4, 7-6 (9), 7-6 (5)

No. 11 Taylor Fritz d. Lorenzo Musetti 6-4, 6-4, 6-3

No. 12 Diego Schwartzman d. Stefan Kozlov 6-3, 6-2, 6-2

No. 15 Reilly Opelka d. Carlos Taberner 7-6 (5), 6-4, 6-4

No. 17 Roberto Bautista Agut d. Attila Balazs 6-1, 6-0, 6-3

Steve Johnson d. No. 18 Grigor Dimitrov 4-6, 5-2 ret.

No. 19 Alex De Minaur d. Hugo Dellien 6-1, 6-3, 7-5

No. 21 Botic Van De Zandschulp d. Feliciano Lopez 6-2, 6-3, 6-3

No. 29 Jenson Brooksby d. Mikhail Kukushkin 6-3, 6-2, 6-3

Nick Kyrgios d. Paul Jubb 3-6, 6-1, 7-5, 6-7 (3), 7-5

Women's Singles

No. 1 Iga Swiatek d. Jana Fett 6-0, 6-3

No. 4 Paula Badosa d. Louisa Chirico 6-2, 6-1

No. 5 Maria Sakkari d. Zoe Hives 6-1, 6-4

No. 11 Coco Gauff d. Elana-Gabriela Ruse 2-6, 6-3, 7-5

No. 12 Jelena Ostapenko d. Oceane Dodin 6-4, 6-4

No. 13 Barbora Krejcikova d. Maryna Zanevska 7-6 (4), 6-3

Qiang Wang d. No. 14 Belinda Bencic 6-4, 5-7, 6-2

No. 16 Simona Halep d. Karolina Muchova 6-3, 6-2

Ajla Tomljanovic d. No. 18 Jil Teichmann 6-2, 6-3

No. 20 Amanda Anisimova d. Yue Yuan 6-3, 6-4

No. 25 Petra Kvitova d. Jasmine Paolini 2-6, 6-4, 6-2

Harmony Tan d. Serena Williams 7-5, 1-6, 7-6 (7)

Full results at Wimbledon.com.

Serena Williams was the big story in her return to the court and she was involved in one of the best matches of the day against Harmony Tan.

Tan outlasted Williams in a competitive first set, while the second set featured some marathon games:

Williams eventually took a 5-0 lead in the second set and closed it out 6-1.

As the extended match continued, the 40-year-old showed incredible endurance but just couldn't keep up with the 24-year-old Tan. Williams fought off match point in the 12th game of the set to force a tiebreak and went up 4-0, but it was Tan who survived down the stretch for the hard-fought victory.

Though both players were unseeded, the first-round battle could end up being the most memorable at Wimbledon.

American Maxime Cressy completed the biggest upset of the day, defeating No. 6 seed Felix Auger-Aliassime, last year's quarterfinalist.

Cressy's serve-and-volley approach helped in this one, finishing 95-of-134 on net points. He saved the only break point he faced over the four-set match, keeping Auger-Aliassime uncomfortable throughout the day.

With wins in two of the three tiebreaks, Cressy did enough to earn his first win at Wimbledon.

Rafael Nadal went from cruising to facing a scare during his match, winning the first two sets before dropping the third and trailing in the fourth against Francisco Cerundolo.

Nadal struggled with his second serve and tallied just 23 winners to 41 unforced errors. The No. 2 seed eventually found his footing, winning five of the last six games to secure the win:

Stefanos Tsitsipas also dropped a set on the way to his first-round win, but he did his part defensively while winning 43 percent of receiving points. It was enough to advance over Alexander Ritschard.

The top seeds in the women's draw faced little resistance as they advanced to the second round.

Iga Swiatek lost just three games on her way to an easy win over Jana Fett, extending her winning streak to 36 matches:

The run includes one Grand Slam title, and she is looking for a second one as the top seed in the ladies' draw.

No. 4 Paula Badosa and No. 5 Maria Sakkari also earned straight-set victories as they proved to be legitimate contenders in this competition.

Simona Halep already won this event in 2019 and could be a threat once again after winning 78 percent of her service points in a win over Karolina Muchova.

The second round of Wimbledon will begin Wednesday with Novak Djokovic and Anett Kontaveit among those in action.