Stefanos Tsitsipas, a semi-finalist at last month's Australian Open, reached the final four of the ATP Rotterdam tournament on Friday with a 4-6, 6-3, 7-5 victory over Karen Khachanov.

World number six Tsitsipas fought back from 3-1 down in the final set and broke his Russian opponent at five games each before sealing a place in the semi-finals.

"He was playing great tennis and I wasn't sure if I would be able to compete," said Tsitsipas who fired 46 winners past his Russian opponent.

"We had great rallies and the quality of tennis was excellent.

"You need to stay as calm as possible in three-setters. I have won a lot in the past and with experience, it gives me an idea of how to play in these tight moments."

Tsitsipas beat Rafael Nadal en route to the Australian Open semi-finals before losing to Daniil Medvedev, who crashed out in the opening round in Rotterdam as top seed.

The second-seeded Greek will next play another Russian in fourth seed Andrey Rublev who battled past French qualifier Jeremy Chardy 7-6 (7/2), 6-7 (2/7), 6-4.

"It was a really tough match against Jeremy," Rublev said in an on-court interview after having had two match points in the second set.

"I will try to do as much as I can to be ready for tomorrow. Stefanos also had two tough matches this week."

Rublev and Chardy fired a combined total of 80 winners in their quarter-final clash.

Borna Coric of Croatia edged Japan's Kei Nishikori 7-6 (7/2), 7-6 (7/4) and will face Hungary's Marton Fucsovics for a spot in the final.

Qualifier Fucsovics defeated Tommy Paul of the United States 6-4, 6-3.