World number two Roger Federer comfortably beat Latvian Ernests Gulbis 6-3, 7-5 to move into the last-eight of the Halle Open where he will meet Germany's Florian Mayer.
The 17-time grand slam winner, preparing for Wimbledon's grass courts, got his first break when Gulbis sent a forehand long to go 4-2 up. He easily held serve to bag the first set.
The pair traded blows in the second set before Federer again broke Gulbis with the world number 86 double faulting at 5-5.
The defending champion, who has won the tournament seven times, fired a forehand winner on his first match point to set up a quarter-final meeting with the German.
Czech Tomas Berdych, the third seed, also advanced, beating Croatian teenager Borna Coric in straight sets, losing just two points on his first serve in the entire match.
Wawrinka knocked out
Meanwhile, French Open champion Stanislas Wawrinka was scythed back to earth by big-serving South African Kevin Anderson on the Queen's Club grass as the Swiss bowed out of the Aegon Championships 7-6(4) 7-6(11).
|Wawrinka lost his first game since winning the French Open earlier this month [Getty Images]
Two metre tall Anderson hurled down 22 aces, the last one on match point, to send Wawrinka spinning to his first loss since he beat world number one Novak Djokovic in spellbinding fashion in the Roland Garros final earlier this month.
Anderson, the world number 17, now has four consecutive wins against Wawrinka, the first of that sequence being the Swiss's first loss after he won the 2014 Australian Open.
Seventh seeded Frenchman Gilles Simon earlier beat Australian teenager Thanasi Kokkinakis 6-4 6-2 despite losing the first nine points of the match.
Simon will face Milos Raonic in the quarter-finals after the Canadian third seed beat Richard Gasquet 6-4 6-7(5) 6-1 despite still feeling some discomfort from the surgery he had on a nerve in his foot that meant he misses the French Open.