Marin Cilic remained on course to retain the Kremlin Cup by Bank of Moscow title on Thursday by recording his 30th match win of the year with a 7-6(3), 3-6, 6-3 victory over Denis Istomin in two hours and three minutes. It was his sixth win in seven meetings over Istomin, who captured his first ATP World Tour title at Nottingham (d. Querrey) in June. Cilic is attempting to reach his first ATP World Tour final in 12 months.

No. 4 seed Philipp Kohlschreiber battled past Russian qualifier Aslan Karatsev 7-6(3), 2-6, 6-4 to earn a spot in the quarter-finals. The 22-year-old Russian took out three compatriots to qualify for the main draw, then defeated former champion Mikhail Youzhny in the first round.

The World No. 207 had Kohlschreiber on the ropes in the opening set, but saw the German break back at love at 6-5 and sneak away with the tie-break. The fourth seed would serve out the win on his third match point after two hours and 22 minutes.

Kohlschreiber will now face Robin Haase, against whom he is 0-1 (2012 Kitzbuehel).

Earlier in the day, Lucas Pouille defeated Daniel Gimeno-Traver 6-1, 7-6(5) and wild card Evgeny Donskoy hit 10 aces in a 6-4, 7-5 win over Ricardas Berankis.