BRISBANE (AP) ― Serena Williams and Maria Sharapova are set to renew their long and not-so-friendly rivalry after advancing to a semifinal match at the Brisbane International, a key warm up tournament for the Australian Open.

The pair played back-to-back quarterfinals on center court Thursday, with third-seeded Sharapova needing two hours to beat 2012 Brisbane champion Kaia Kanepi of Estonia, 4-6, 6-3, 6-2. She dropped three service games in the first set and another to open the second before finding her range and staging her comeback against the No. 30-ranked Kanepi.

Top-ranked Williams, the defending champion, was next on court and didn’t lose a point on serve in the first set en route to a 6-3, 6-3 win over ninth-seeded Diminika Cibulkova of Slovakia.

Williams has a 14-2 record and 13-match win streak against Sharapova, beating the Russian most recently in last year’s French Open final.

Any friendship the pair had soured when they traded personal barbs relating to their romantic relationships ahead of last year’s Wimbledon, where Sharapova made an early exit. She only played one match after that in 2013 and spent the latter months of the year recovering from a right shoulder problem.

Sharapova has only played two matches since August, both this week.

Williams had a spectacular year, meanwhile, winning 78 of her 82 matches and capturing 11 titles, including two majors to increase her career total to 17.

As far as any grudges go, Williams told a news conference Thursday: “It’s very difficult I think for anyone to be best buddies when you’re so competitive.”

“But I don’t have a problem with anyone,” she said. “I don’t take jabs or anything. I am who I am and I don’t hide anything.”

Qatar Open

DOHA (AP) ― Third-seeded Andy Murray, playing in his first tournament since back surgery in late September, was upset by Florian Mayer of Germany 3-6, 6-4, 6-2 at the Qatar Open on Wednesday.

Murray was leading 6-3, 3-0 when the 40th-ranked Mayer started to play more aggressively, going for winners on nearly every shot. Murray’s lead evaporated as he only won three of the last 15 games in the one hour, 51 minute match.