Nick Kyrgios beat world number six Stefanos Tsitsipas at the Halle Open – smashing his racquet and arguing with the umpire during the match.
The Australian, ranked 65th, came back to beat Greek Tsitsipas 5-7 6-2 6-4.
Kyrgios, 27, smashed his racquet after losing the opening set in Germany.
He then got into an argument with the chair umpire in the second set and received a warning for time-wasting – a delay Kyrgios said was due to needing to wipe sweat from his hands.
It is a second successive quarter-final for Kyrgios as he prepares for Wimbledon, having gone on to reach the semi-finals in Stuttgart last week, and he will face Spanish sixth seed, Pablo Carreno Busta, next.
The Australian was given a penalty after smashing his racquet and exchanging words with the crowd as he lost to Andy Murray in Stuttgart. Kyrgios later alleged he was racially abused by a spectator.