Rotterdam, The Netherlands (SportsNetwork.com) - Top seed and reigning champion Juan Martin del Potro defeated last week's Montpellier titlist Gael Monfils in a marquee opening-round affair Wednesday at the $1.85 million ABN AMRO World Tennis Tournament.

The former U.S. Open champion del Potro handled the unseeded Frenchman Monfils in 7-6 (8-6), 6-3 fashion on the indoor hardcourts at Ahoy Rotterdam.

Del Potro beat Frenchman Julien Benneteau in last year's Rotterdam finale and was the runner-up here the year before.

Meanwhile, fourth-seeded Richard Gasquet snuck past Dutchman Thiemo de Bakker 6-7 (5-7), 7-6 (7-2), 6-3 and sixth-seeded German Tommy Haas overcame Spanish left-hander Fernando Verdasco 6-7 (4-7), 7-6 (7-1), 7-5 to reach the second round. Gasquet was last week's runner-up to his fellow Frenchman Monfils in Montpellier, while Haas is fresh off his runner-up finish in Zagreb.

Also in the opening round, Austrian qualifier Dominic Thiem outlasted Finn Jarkko Nieminen 6-4, 4-6, 6-4 and Frenchman Nicolas Mahut doused German Daniel Brands 7-5, 6-3.