Moscow - US Open champion Marin Cilic cruised comfortably into the Kremlin Cup semi-finals with a confident straight-sets victory over sixth-seed Tommy Robredo of Spain on Friday.
The 26-year-old Croat, a career-high eighth in the ATP rankings, fired 10 aces to beat Robredo 6-3, 6-3 to keep alive his chances of making it into the season-ending ATP World Tour Finals in London.
Second-seed Cilic, sixth in the race to London needs to reach the final at this combined ATP and WTA event to increase his tally, and broke Robredo's serve for a one-set lead in 31 minutes.
The opponents traded breaks early in the second set before big server Cilic moved up a gear to produce two more breaks to win the set and the match in one hour 16 minutes.
"My match today was a little higher that my first one here," Cilic said.
"Robredo is very dangerous from the back. He's a very difficult player to oppose and today I had to play much longer than I expected.
"I'm really happy that I managed to win in two sets."
In the match for a place in his fifth final of the season Cilic will face last year's runner-up Mikhail Kukushkin of Kazakhstan, who continued his heroics on the hard courts of Moscow's Olympic venue by beating the 2009 champion Mikhail Youzhny of Russia 1-6, 7-6 (7/5), 6-0.
In the other semi-final Latvia's third seed Ernesto Gulbis, who edged eighth seed Italian Andreas Seppi 7-6 (8/6), 4-6, 7-6 (7/3), will take on Spaniard Roberto Bautista-Agut, seeded fifth here, winner of a match with Lithuanian qualifier Ricardas Berankis 7-5, 6-3.
In the WTA section of the event the fourth seed Czech Lucie Safarova advanced into the last four with a straight-sets win 6-4, 7-5 over fifth seeded local crowd's favourite Svetlana Kuznetsova.
"When we were walking on court I remembered that she beat me in Fed Cup here," this year's Wimbledon semi-finalist Safarova said. "There was a huge will for me to change that memory and I think we played a really good match."
"I've played well in my first two matches here and I'm looking forward to tomorrow. I hope I can keep improving my play with every match here."
In Saturday's second semi-final Safarova will meet Romania's Irina-Camelia Begu, who battled back from a set down to oust Bulgaria's Tsvenana Pironkova 1-6, 6-3, 6-2.
In the other last four encounter Czech unheralded teenager Katerina
Siniakova, who beat Italy's Camila Georgi in a three-hour marathon 7-6
(7/3), 4-6, 7-5, will clash with sixth seeded Russia's Anastasia
Pavlyuchenkova, winner of a match against compatriot Vitalia Diatchennko
6-1, 3-6, 6-3.
Collated results on Friday from the Kremlin Cup ATP and WTA tournaments (x denotes seeding):
Men
Quarter-finals
Roberto Bautista (ESP x5) bt Ricardas Berankis (LTU) 7-5, 6-3
Ernests Gulbis (LAT x3) bt Andreas Seppi (ITA x8) 7-6 (8/6), 4-6, 7-6 (7/3)
Mikhail Kukushkin (KAZ) bt Mikhail Youzhny (RUS x7) 1-6, 7-6 (7/5), 6-0
Marin Cilic (CRO) bt Tommy Robredo (ESP) 6-3, 6-3
Women
Quarter-finals
Katerina Siniakova (CZE) bt Camila Giorgi (ITA) 7-6 (7/3), 4-6, 7-5
Lucie Safarova (CZE x4) bt Svetlana Kuznetsova (RUS x5) 6-4, 7-5
Irina Begu (ROM) bt Tsvetana Pironkova (BUL) 1-6, 6-3, 6-2
Anastasia Pavlyuchenkova (RUS x6) bt Vitalia Diatchenko (RUS) 6-1, 3-6, 6-3