ROTTERDAM, Netherlands (AP) Second-seeded Marin Cilic of Croatia had 10 aces in a 7-6 (5), 6-4 win against Denis Istomin of Uzbekistan in the first round of the World Tennis Tournament on Monday.
Istomin saved six break-point chances in the second set, but conceded the only break as Cilic got on top.
Cilic, the 2014 U.S. Open champion, did not face a single break-point in the match. He is looking to bounce back from a second-round exit to German teenager Alexander Zverev at the Open Sud de France last week.
Countryman Ivan Dodig joins Cilic in the next round after beating seventh-seeded Benoit Paire of France 6-3, 7-6 (4).
Roger Federer was scheduled to play here, but recently had knee surgery, meaning that Frenchman Richard Gasquet is now top seed.