Cincinnati - Andy Murray overcame post-Olympic fatigue by winning his 21st straight match to reach the semi-finals of the ATP-WTA Cincinnati Masters with a 6-4, 6-4 victory over Bernard Tomic on Friday.
Top seed Murray, running out of puff after claiming his second Olympic gold medal in Rio, grabbed his left hip in the opening game against Tomic, but soon settled in.
The world number two won his fifth match over the Australian and stands 32-1 since losing to Novak Djokovic in May in Madrid.
"I knew that coming straight from the Olympics I was going to be tired. But I've still managed to win," Murray said.
"Conditions help a bit. There are not a lot of long rallies. I have a few days off when this week is done and then I'll prepare for the US Open."
Murray next faces fourth seed Canadian Milos Raonic, who beat Dominic Thiem 6-3, 6-4. The Scot leads the series 8-4, beating Raonic four times in 2016 including the Wimbledon final.
Raonic advanced to his seventh semi-final of the season in 68 minutes.
The 25-year-old finished with 32 winners, while Thiem, with four 2016 titles, managed only 10 winners and failed on two break point chances.
"I definitely executed well. I did quite a few things well today," Raonic said. "I've practised with him many times, so to some extent I have an understanding of his game, like he has of mine."
Former US Open champion Marin Cilic reached his first Masters semi-final, advancing when Croatian compatriot Borna Coric retired with fatigue after losing the opening set 6-2.
"Today on the court I felt great," Cilic said. "It's tougher obviously to control the ball during the day. It flies much more.
"I felt really, really good on the court this week - obviously it shows on the scoreboard."
Bulgarian Grigor Dimitrov put out new US number one Steve Johnson in straight sets, 7-6 (10/8), 6-2.
Both players came into the quarter-finals off the back of wins over seeds.
Dimitrov knocked out number two seed Stan Wawrinka in the third round, while Johnson beat French seventh seed Jo-Wilfried Tsonga.
Dimitrov now faces Cilic, who has won two of their three matches.
Women's Olympic silver medallist Angelique Kerber stands just two wins away from number one after defeating Carla Suarez Navarro 4-6, 6-3, 6-0.
Kerber could overhaul Serena Williams if she wins the title on Sunday.
"It all feels amazing, I'm seeing all the hard work of the last few years paying off," said Kerber, 28, who beat Williams in the final of the Australian Open but lost to her at the same stage at Wimbledon.
"This is a moment for which I've been dreaming -- and now I'm living the dream."
Kerber will play 2015 finalist Simona Halep after the Romanian broke number five Agnieszka Radwanska eight times in a 7-5, 6-1 win.
Kerber needed a fightback against Suarez Navarro to post her 46th victory of the season.
"It was not so easy to turn it all around in the second set. But I never doubted my game, I knew I could turn the match."
Czech fifth seed Karolina Pliskova advanced over Russian seventh seed Svetlana Kuznetsova 6-3, 4-6, 6-2 and next plays fourth seed Garbine Muguruza, the French Open champion who beat Hungarian Timea Babos 6-4, 6-3.
Results from the sixth day of the ATP Cincinnati Masters and WTA hardcourt tournament on Friday (x denotes seeded player):
Milos Raonic (CAN x4) bt Dominic Thiem (AUT x8) 6-3, 6-4
Grigor Dimitrov (BUL) bt Steve Johnson (USA) 7-6 (10/8), 6-2
Marin Cilic (CRO x12) bt Borna Coric (CRO) 6-2, retired
Andy Murray (GBR x1) bt Bernard Tomic (AUS) 6-4, 6-4
Angelique Kerber (GER x2) bt Carla Suarez Navarro (ESP x9) 4-6, 6-3, 6-0
Karolina Pliskova (CZE x15) bt Svetlana Kuznetsova (RUS x7) 6-3, 4-6, 6-2
Garbine Muguruza (ESP x4) bt Timea Babos (HUN) 6-4, 6-3
Simona Halep (ROM x3) bt Agnieszka Radwanska (POL x5) 7-5, 6-1