No. 2 seed Anett Kontaveit won her first match since April on Monday, defeating Bernarda Pera 7-5, 6-1 in the opening round of Wimbledon.
Also moving on was the No. 3 seed, Ons Jabeur of Tunisia, who posted a quick 6-1, 6-3 victory over Mirjam Bjorklund of Sweden.
American Danielle Collins, the No. 7 seed, wasn't as fortunate and became the first woman seeded in the Top 10 to be eliminated at the All-England Club in London. Unseeded Marie Bouzkova of the Czech Republic topped Collins 5-7, 6-4, 6-4.
Kontaveit, of Estonia, battled COVID-19 this spring and was playing in her first match since falling in the first round of the French Open last month.
"It's been pretty exciting, being seeded second. ... I'm really excited to be playing again and really happy that I can compete here," Kontaveit said. "A month ago, I was really having a hard time. I really wouldn't have come here if I wasn't feeling like I could play a match, compete at the highest level.
"I've been feeling better. I mean, there's some times I felt dips in my energy from time to time. But I've been managing it, trying to prepare the best that I can (and) take the most out of the situation I'm in."
Next up for Kontaveit will be German Jule Niemeier, who won her first Grand Slam match against Xiyu Wang of China 6-1, 6-4.
Reigning U.S. Open champion Emma Raducanu, the 10th seed, thrilled the home crowd with her 6-4, 6-4 win over Alison Van Uytvanck of Belgium.
The 19-year-old Raducanu moved to 5-0 in her career in the first round of Grand Slam tournaments. Last year, she advanced to the fourth round at Wimbledon when she was a wild-card entry ranked outside the Top 300.
Now, she's No. 11 in the world, and was delighted to play on the grass courts in London.
"From the moment I walked out through those gates, I could really just feel the energy and the support and everyone was behind me from the word 'go,'" she said. "I just really tried to cherish every single point on there, played every point like it could have been one of my last on that court."
In the second round, she'll meet Caroline Garcia of France, who was pushed to a third-set tiebreaker by Yuriko Miyazaki of Great Britain.
Other seeded players to win in the opening round were No. 15 seed Angelique Kerber of Germany, No. 24 Elise Mertens of Belgium, No. 26 Sorana Cirstea of Romania, American No. 28 Alison Riske and No. 29 Anhelina Kalinina of Ukraine.
Seeded players who were knocked out included No. 22 Martina Trevisan of Italy, No. 23 Beatriz Haddad Maia of Brazil and No. 31 Kaia Kanepi of Estonia.
Haddad Maia was upset by Kaja Juvan of Slovenia in three sets. Haddad Maia won on the grass courts of Nottingham and Birmingham leading up to Wimbledon.
--Field Level Media