New mother Victoria Azarenka reached the last 16 of Wimbledon with a nerve-jangling 3-6 6-1 6-4 win over home favourite Heather Watson.
Azarenka, the former world number one, who is returning to tennis after the birth of her son in December, was stung into action after Watson had ridden a patriotic wave to the first set.
Despite throwing in three double-faults to Watson's one, she broke twice to win the second and set up a decider.
Watson kicked off the third set serving, and pushed her nose in front. The Briton was finding it tough to hold, though, while Azarenka breezed through her service games.
The Belarussian clinched a break in a 10-minute seventh game, but Watson hit straight back to level it 4-4 and set off a roar within the arena. But it was only a temporary reprieve, as Azarenka punched straight back before serving out.
"I really stepped up in the key moments," she said. Azarenka will next play either second-seeded Romanian Simona Halep or China's Peng Shuai for a place in the quarters.
Johanna Konta kept the flag flying for British women at Wimbledon, reaching the last 16 with a comfortable 6-4 6-1 victory over Greece's Maria Sakkari.
The sixth seed announced her aggressive intentions from the first game when she twice drew her opponent into the net before passing her with crisp cross-court winners to break serve. Roared on by a packed Court One crowd, she grew stronger and stronger as the match progressed, dominating the baseline duel.
A nervous-looking Sakkari, aged 21 and ranked 101 in the world, compounded her plight with a string of unforced errors, spraying the ball long and wide on decisive points.
Konta will next play France's Caroline Garcia, is one of the favourites to lift the title.
