Dmitry Tursunov pulled off an extraordinary five-set win over fifth seed Ivan Ljubicic to reach round four for the second successive year.
Tursunov is the 27th seed at this year's Championships
Ljubicic seemed in total control of the match after taking the first two sets but Tursunov breezed through the third to change the course of the match.
He took the fourth on a tie-break and rattled through the fifth to complete a superb 5-7 4-6 6-1 7-6 (8-6) 6-2 win.
Ljubicic was in the third round for the first time in seven appearances.
Sixth seed Lleyton Hewitt claimed a 6-1 6-4 6-4 victory over Belgium's Olivier Rochus to seal a place in the last 16.
The 2002 champion took the first set 6-1 in just 25 minutes and drove home his advantage when he broke early in the second to build a two-set lead.
The Australian was made to work harder against 26th seed Rochus in the third but broke at 4-4 before sealing it 6-4.
Right-hander Hewitt now faces Spain's David Ferrer, who became the second man of the day to hit back from a two-set deficit and go through.
The 23rd seed, already enjoying his best-ever Wimbledon, recovered to beat 10th seed Fernando Gonzalez 4-6 2-6 6-2 6-3 6-4.
Seventh seed Mario Ancic ignored the fact that his rain-interrupted match had to move court to complete a 7-6 (7-5) 6-7 (5-7) 6-1 6-3 win over Stanislas Wawrinka.
The match started on Centre Court on Friday but was switched to Court One to allow the maximum chance of all the singles matches finishing on Saturday.
The players resumed at one-set all but Ancic quickly took control and needed just 66 minutes to finish proceedings.
In the fourth round he will take on unseeded Novak Djokovic.
Meanwhile 22nd seed Jarkko Nieminen reached the fourth round for the first time after hitting back from a set down to beat Philipp Kohlschreiber.
Nieminen, who beat Britain's Martin Lee in round two, won 1-6 6-2 6-3 7-6 (7-4).