Djokovic falls to inspired Opelka in Brisbane quarter-finals

Novak Djokovic's hunt for a landmark 100th ATP title ended with a whimper following an unexpected 7-6(6) 6-3 defeat by big-serving American Reilly Opelka in the Brisbane International quarter-finals on Friday.

Defeat was a huge blow for the Serb, who will bid to join Roger Federer (103) and Jimmy Connors (109) as players who have won at least 100 titles when he heads to the Australian Open, where he will also seek a 25th Grand Slam trophy.

Djokovic saved three breakpoints in stifling conditions to go 5-4 up but lost the opening set in a tough tiebreak as Opelka cranked up his serve and seized early control of his maiden tour meeting against the 37-year-old.

Opelka broke for a 3-1 lead in the next as Djokovic looked rattled by the 6ft 11 in (211 cm) American, who pulled off some spectacular winners on both flanks.

The final blow came on Opelka's serve and the 27-year-old fittingly finished the match with a powerful ace.

Up next for Opelka is Giovanni Mpetshi Perricard in what promises to be an explosive battle after the Frenchman sent down 19 aces in his 7-5 7-6(5) win over Czech Jakub Mensik to take his tournament tally to 75.

Defending champion Grigor Dimitrov went through after Jordan Thompson retired while trailing 6-4 2-1, while Jiri Lehecka made quick work of Nicolas Jarry, securing a 6-4 6-4 victory.

SLOW START

In the women's event, reigning Australian Open champion Aryna Sabalenka shrugged off another slow start and some shaky moments on her forehand late on to get past Marie Bouzkova 6-3 6-4 for her third straight-sets win this week.

Up next for Sabalenka is Russian 17-year-old Mirra Andreeva, who cut short Ons Jabeur's comeback from form and injury issues with a 6-4 7-6(2) win.

Anhelina Kalinina saved a matchpoint to end the run of local wildcard Kimberly Birrell with a 4-6 6-1 7-5 win to book a clash with Polina Kudermetova, who beat Ashlyn Krueger 7-6(5) 6-3.

Four-times Grand Slam champion Naomi Osaka made her first semi-final in nearly three years after rallying to a 6-7(2) 6-1 6-2 victory over Hailey Baptiste at the Auckland Classic.

"I think the key focuses I had were just to have a lot of belief and confidence in myself," said Osaka, who returned to the WTA Tour 12 months ago after a maternity break.

"I put a lot of work in throughout last year, and even though the results didn't show it, I think I'm just continuing to try as hard as I can and see where it gets me."