The third day at Wimbledon saw 38 matches on the Ladies' side as the first round was completed and the second round began.
Sabalenka, Svitolina need three sets to move on; Swiatek, Pliskova cruise
Ove the course of the two hour, six minute battle, the Belarusian converted on five of her six break point chances while Boulter only took three of her 12 opportunities.
"I'm proud that I could actually get through this match because I was really emotional in the beginning", she said following the victory. [Boulter] was playing really great."
Svitolina needed an hour, 41 minutes to see off qualifier Alison Van Uytvanck 6-3, 2-6, 6-3 with the Ukrainian hitting 34 winners.
The Belgian broke in the opening game of the match, but Svitolina broke twice to claim a 4-2 advantage before easing through the remainder of the set.
It was the world number 57's forehand that did the damage as she broke for a 3-1 lead and closed out the set with a winner from that side, leveling the match.
From 2-2 in the deciding set, Svitolina broke twice, mixing up her shots to great effect as she saw off the feisty Belgian to reach the second round.
"I think the return was quite good for me today", she said in her post-match press conference. "I was striking the ball really good. On the important moments, I think I was calm. This was very important for me today."
Swiatek needed just over an hour to dismiss 2010 finalist Vera Zvonareva 6-1, 6-3, converting five of 11 break point opportunities.
Pliskova routed Donna Vekic 6-2, 6-2 to book her place in the third round. The Czech never faced a break point in defeating the Croat at a second straight major.
Brengle, Cornet, Juvan pull off major upsets
In just 45 minutes, Kenin made a swift exit at the hands of Madison Brengle, who defeated her compatriot 6-2, 6-4.
The 2020 Australian Open champion was undone by 41 errors, marking the most unforced errors per minute in the history of the tournament at 0.91.
"I really did not find my game", she said after the defeat. "Of course, she played well. I just feel like leading up to Wimbledon, I clearly did not have enough preparation on the grass. I just didn't have enough preparation on grass, and that's unfortunate."
For the second time in three weeks, Andreescu was beaten by Alize Cornet with the Frenchwoman claiming a 6-2, 6-1 victory on one hour, 22 minutes.
From 2-2 in the first set, Cornet won the final four games, all going to deuce and won 12 points in a row to go in front 4-0 in the second set, cruising the rest of the way.
Bencic fell in an hour, 20 minutes to world number 102 Kaja Juvan with the Slovenian winning 6-3, 6-3. Both players had 22 winners, but Bencic committed 28 unforced errors, including six double faults, to Juvan's 13.
Samantha Murray Sharan joined Boulter on the sidelines with a 6-3, 6-3 defeat at the hands of Sorana Cirstea but there was a win for Emma Raducanu on her major debut, the wild card knocking off Vitalia Diatchenko 7-6 (4), 6-0.
Other seeded winners and losers
Seeds to win in the first round were 12th seed Victoria Azarenka, who routed Kateryna Kozlova 6-1, 6-3, 16th seed Anastasia Pavlyuchenkova, crushing Ana Bogdan 6-2, 6-2, 19th seed Karolina Muchova defeating Shuai Zhang 6-3, 6-3, 30th seed Paula Badosa, a 6-2, 5-7, 6-2 victor over countrywoman Aliona Bolsova and 31st seed Daria Kasatkina, who needed three sets to dispatch Patricia Maria Tig 6-0, 3-6, 6-3.
Second round seeded winners were 11th seed Garbine Muguruza 6-1, 6-4 over Lesley Pattinama Kerkhove, 13th seed Elise Mertens dominating Lin Zhu 6-2, 6-0, 18th seed Elena Rybakina getting past Claire Liu 6-4, 6-4, 21st seed Ons Jabeur scoring a 7-5, 6-0 win over five-time champion Venus Williams and 23rd seed Madison Keys, a 6-1, 6-4 winner over Lauren Davis.
Not as fortunate were 22nd seed Jessica Pegula, beaten by the red-hot Liudmila Samsonova 6-4, 3-6, 6-3, 24th seed Anett Kontaveit, dumped out by Marketa Vondrousova 2-6, 6-4 6-2, 26th seed Petra Martic a 7-5, 6-7 (7), 6-3 loser to Irina-Camelia Begu and 32nd seed Ekaterina Alexandrova, who fell to Maria Camila Osorio Serrano 7-5, 6-2.
Other first and second round results
To complete the first round, Magda Linette overcame Amanda Anisimova 2-6, 6-3, 6-1, Kristyna Pliskova rallied past Astra Sharma 3-6, 6-4, 6-4, Clara Burel, who routed Ellen Perez 6-2, 6-2, Camila Giorgi, victor over Jil Teichmann by the same 6-2, 6-2 score, Jelena Ostapenko, brushing aside Leylah Annie Fernandez 6-1, 6-2, Sara Sorribes Tormo, who slipped by Ana Konjuh 6-3, 3-6, 6-3, Katerina Siniakova blasting Yafan Wang 6-1, 6-0, Ajla Tomljanovic triumphing over Greet Minnen 6-2, 7-6, Anastasija Sevastova over Zarina Diyas 6-4, 6-1, Nao Hibino outlasting Bernarda Pera 6-1, 5-7, 6-3 and former quarterfinalist Coco Vandeweghe beating Olga Govortsova 6-4, 6-2.
Second round winners were Sloane Stephens, who continues her good form with a 7-5, 6-3 victory over lucky loser Kristie Ahn, Tereza Martincova, a 6-3, 7-6 (4) winner against Nadia Podoroska and Viktorija Golubic dominating Danielle Collins 6-2, 6-0.