Elise Mertens stunned second seed Elena Rybakina after claiming an eye-catching, straight-sets victory in the third round at Wimbledon.

Belgium's Mertens, the 25th seed at this grass-court major, battled hard to overcome the 2022 Wimbledon champion, managing a 7-6 (7-4) 6-1 victory in just over 90 minutes of action on Saturday.

Her reward for the largest shock of the tournament so far will be a fourth-round meeting with world number 23 Marie Bouzkova, who survived a three-hour encounter to beat Liudmila Samsonova 4-6 7-6 (7-3) 6-4.

Mertens successfully defended three break points during a hard-fought opening before eventually breaking Rybakina's serve to go 4-3 up, though her opponent responded in the game after to level again.

The pair traded breaks once again to send the first set to a tie-break decider, in which Mertens squandered two set points before holding with the ball in hand to strike the first blow.

Mertens came flying out of the blocks with the momentum behind her, breaking twice to comfortably move into a 5-1 second-set lead before finally getting over the line with her third match point.

Maria Kostyuk also secured her passage to the next stage with a 6-2 4-6 6-1 victory over 23rd seed Emma Navarro, with the Ukrainian reaching the fourth round at Wimbledon for the first time in her career.

Rybakina's struggles continue

Since winning her second WTA title of the season in Stuttgart in April, two-time major winner Rybakina has now failed to go beyond the quarter-finals in her last six tournaments.

Champion of this grass-court major four years ago, and winner of this year's Australian Open against Aryna Sabalenka, Rybakina had won her previous six meetings with Mertens, but struggled for rhythm here.

She may be concerned by her recent run, also suffering a second-round defeat in Berlin against wildcard Alexandra Eala and losing to the unseeded Yuliia Starodubtseva at last month's French Open.

Rybakina may also be frustrated by her failure here, having failed to go past the third round at Wimbledon last year.

By contrast, this triumph marks positive progress for Mertens – she had never beaten a top-10 player on grass before Saturday.

The 30-year-old's best run in a grand slam singles tournament came in a 2018 Australian Open semi-final appearance, and having won twice in the doubles at Wimbledon, she may hope to find solo success now.