Moscow - Kremlin Cup top seed and defending champion Marin Cilic battled through to the quarter-finals with a hard-fought three sets success over Uzbek Denis Istomin in Moscow on Thursday.
The 27-year-old Croat, seeking his first win of the season and career 14th title in Moscow, prevailed 7-6 (7/3), 3-6, 6-3 in two hours to record his sixth win over Istomin in seven meetings.
After taking the opening set in a tiebreak in 56 minutes Cilic lost his grip in the second allowing the 29-year-old Istomin to break twice to level at one set all after one hour 30 minutes on court.
But in the deciding set Cilic, 14th in the ATP rankings, moved up a gear to race to a 4-0 advantage which let him to book a place in the quarter-finals.
"In the last few matches with Denis (Istomin) I always experienced problems as his style of play doesn't suit me," Cilic said.
"Today it was another very tough match as in the first two sets I didn't have any break points.
"In the third set I felt that his game dipped a little and that was enough for me to make the deciding advantage.
"I feel that I'm not too far from my top form and I hope in the near future I will be able to play much, much better."