Greece's Stefanos Tsitsipas celebrates his victory against Switzerland's Roger Federer during their men's singles match on day seven of the Australian Open tennis tournament in Melbourne on January 20, 2019. (Photo by DAVID GRAY / AFP) / -- IMAGE RESTRICTED TO EDITORIAL USE - STRICTLY NO COMMERCIAL USE --

ROTTERDAM, Netherlands — Rising Greek star Stefanos Tsitsipas said he “lost to himself” after suffering a shock defeat to Bosnian Damir Dzumhur at the ATP event on Wednesday.

The 20-year-old, who dumped out Roger Federer en route to the Australian Open semifinals last month, saved two match points late in the third set but still slumped to a 6-4, 1-6, 7-5 loss.

It was Dzumhur’s first win since October after a run of four straight defeats, and Tsitsipas was left frustrated by an erratic display.

“I lost to myself, not to him,” said the world no. 12.

“He fools you, waits for you to make mistakes. He stands eight meters behind the baseline and plays with your strengths. He played nothing crazy or special, but you don’t get any rhythm with him.

“The momentum was on my side but he kept putting the ball into the court and running.”

Tsitsipas was seeded third at the Ahoy Arena, but has now lost three of his last four matches after following his Melbourne semifinal thrashing by Rafael Nadal with a quarterfinal exit from the hands of Gael Monfils in Sofia last week.

Stan Wawrinka, the 2015 champion, ended a three-match losing run against Milos Raonic as he defeated the fourth-seeded Canadian 6-4, 7-6 (7/4) to reach the Last Eight.

Wawrinka, ranked 68th after spending last season recovering and rehabbing from two 2017 knee operations, is fast gaining momentum in 2019.

The 33-year-old Swiss saved the only break point he faced while holding big server Raonic to a relatively modest 15 aces.

“I was moving much better in this match than some of the others against him,” said the three-time Grand Slam title winner.

“This was my best match in many months. Some of my losses this season were close calls. I’m trying to push myself, I’m looking for results.”

Wawrinka will play his second quarterfinal of the season after Doha when he takes on Denis Shapovalov after the Canadian teenager beat former champion Tomas Berdych 6-4, 6-3.