Madrid, May 3 (IANS): Stefanos Tsitsipas advanced to the quarter-finals of the Madrid Open after beating Bernabe Zapata Miralles in the early hours of Wednesday morning, here.

The Greek conceded three service breaks to World No. 42 Zapata Miralles but remained in charge throughout thanks to seven service breaks of his own in a 6-3, 6-1 victory.

"It was definitely tricky; he came out pretty strong in some of my service games... "It's never easy playing against Spaniards who know the surface very well," Tsitsipas said.

"It seemed kind of chaotic in the beginning but then I gave myself time to think and construct my points," he added.

The two-time Monte-Carlo champion dominated his opponent's serve, restricting Zapata Miralles to a first-serve winning percentage of 38 per cent. Tsitsipas, who has reached the quarter-finals or better of his past 10 clay-court events, will next meet Germany lucky loser Jan-Lennard Struff.

German Struff continued his hot clay-court, charging into his second consecutive ATP Masters 1000 quarter-final after a tight 7-6(7), 6-7(7), 6-3 win over Argentine Pedro Cachin.

After rallying from 1-4 in the second set to force a tie-break, Struff missed the opportunity to close out the match in straight sets when he held match point at 6/7 in the 'breaker. But he carried the momentum of his comeback into the third set to twice break Cachin to close out the match in two hours and 28 minutes.

Struff lost to Aslan Karatsev in qualifying but came into the main draw as a lucky loser. He has surged 24 places this week to No. 41 in the ATP Live Rankings. Should he reach the semi-finals he is projected to be within a couple of spots of his career-high mark of No. 29.