Dutch tennis player Robin Haase surprised one and all – including his opponent, Germany’s Peter Gojowczyk – with a bizarre serve during their quarter-final clash at the ASB Classic in Auckland on Thursday.

Instead of the orthodox overhand serve, Haase chose to surprise Gojowczyk with an underhand serve. And although the latter managed to slice-return the ball, the former set it up well enough to finish the point with a down-the-line forehand.

Haase went to pull off a 6-4 6-4 conquest in an hour and 24 minutes, thereby sealing his first semi-final berth at the ATP 250 event in New Zealand.

It’s an underhand serve from @robin_haase!

????????#ASBClassic pic.twitter.com/qiWuyNJwPG

— Tennis TV (@TennisTV) January 11, 2018

This is not the first time that the 30-year-old has done something like that on the court.

Haase amused spectators at the Paris Masters in November last year when he unleashed a left-handed forehand during his 5-7 4-6 pre-quarterfinal defeat to Argentina’s Juan Martin del Potro.

“I’ve Never Seen that Before in My Life.” ????#LeftIsRight pic.twitter.com/mXSDAWLoem

— Tennis TV (@TennisTV) November 2, 2017