tie-break

While she was also helped by Lamens' errors, Raducanu maintained her composure to take her tie-break record to 6-1 this year.

Raducanu was often unable to cope with Lamens' baseline power in the opening set but recovered from a break down - and saved three more break points in the ninth game - to drag her opponent into a tie-break.

Breathing heavily and wiping his face on a towel between every point, Djokovic could only watch as Mensik sent three excellent serves past him to force a tie-break, before the Serb whacked his thigh with his racquet after dropping the opening point in it.

But the 24-time Grand Slam champion had to dig deep in the second, with some impressive serving allowing him to recover from 5-2 down to force a tie-break and clinch the win.

But she showed remarkable mental toughness to hold serve for 6-5, managing to step up her level again in a superb tie-break, before Pegula outlasted her in the decider.