Marin Cilic, seeded second, needed nearly two hours to defeat John Millman 6-3, 4-6, 6-3 and advance to the quarter-finals of the Shenzhen Open on Thursday. The 2014 US Open champion improved to 24-14 in 2015 and remains in contention for a first ATP World Tour title since winning in Moscow a year ago (d. Bautista Agut).

Cilic controlled the first set, sweeping all 13 first-serve points and breaking his Australian opponent twice in as many opportunities. Millman improved his first serve percentage from 57 per cent to 67 per cent in the second set and converted on his lone break point to push the match to a decider. 

“I was generally happy with my performance in the first set,” said Cilic. “In the first game of the second set, he hit good returns. Then he served really well after that. It was not easy to get back in the match. The conditions are really humid, so you have to be prepared. It’s more demanding physically, but I served well and that helped me get some free points at critical moments.”

The Croat, No. 14 in the Emirates ATP Rankings, struck six of his 12 total aces in the final set, and converted on his first match point to take the pair’s initial FedEx ATP Head2Head meeting.

Next up for Cilic is Korean Hyeon Chung, who needed just 56 minutes to down Aljaz Bedene, 6-2, 6-0 to reach his first ATP World Tour quarter-final. The 19 year old went 6-for-8 on break points and earned his 10^th tour-level win of the season (10-9). Currently World No. 58, Chung is aiming to reach No. 35 and become the highest-ranked male player in history from South Korea.

Cilic leads the rivalry 1-0, having defeated Chung 7-6(2), 6-3 in Washington two months ago.

In what has been the best season of his career, fifth seed Adrian Mannarino reached his sixth ATP World Tour quarter-final as he defeated Chinese wild card Yan Bai 7-5, 7-6(7).

The 27-year-old Frenchman reached a career-high No. 27 in the Emirates ATP Rankings in July, in a year that has seen him reach his first ATP World Tour finals in Auckland (l. to Vesely) and Bogota (l. to Tomic).

Mannarino notched his 27th win of 2015 as he edged the No. 266-ranked Bai in one hour and 50 minutes. The left-hander converted three of his seven break points as he denied Bai a place in his first ATP World Tour quarter-final.

Mannarino goes on to face fourth seed Guillermo Garcia-Lopez, who dismissed Lukas Rosol 6-4, 6-3 in 76 minutes. The Spaniard, who improved to a 27-19 match record on the season, is chasing his third ATP World Tour title of the season this week to add to triumphs in Zagreb (d. Seppi) and Bucharest (d. Vesely).