Australian 12th seed Bernard Tomic has been beaten 4-6 6-3 6-4 by South African Kevin Anderson at the Toronto Masters.
Anderson recovered from his first set loss with the help of 26 aces to overcome Tomic to reach the quarter-finals.
Tomic marched into the third round of the tournament on Wednesday when he saw off local favourite Steven Diez 6-3 7-6 (7-4) in the pair’s first meeting.
Anderson will next line up against Swiss second seed Stan Wawrinka who on Thursday posted a 7-6 (7-3) 6-2 win over Jack Sock.
“I feel positive now after this win – let’s see what happens,” Wawrinka said after advancing in less than 90 minutes and winning his 30th game of 2016.
The 31-year-old, who owns Roland Garros and Australian Open titles, won the challenging first set in a tiebreaker before bringing home the victory in straights.
The 2008 Beijing doubles gold medallist alongside Roger Federer admitted that the Olympics is never far from his mind, with his departure for Rio set at the end of his play this week.
“I have lots of goods memories from Beijing. I’m looking forward to playing the Olympics again. I really enjoyed the experience.”
Third seed Kei Nishikori said he is still not on top form after a Wimbledon rib injury, but showed little apparent discomfort as he reached the last eight 6-3 6-4 against American Rajeev Ram.
“I think it’s good, not maybe 100 per cent yet but feeling pretty strong,” he said of his physical problem.
Nishikori improved to 37-11 on the season with one title at Memphis and two additional finals to far in 2016.