Flushing Meadows, NY (SportsNetwork.com) - Stan Wawrinka was a second-round winner on a hot Wednesday at the 2014 U.S. Open.

Wawrinka, the No. 3 seed, defeated Brazilian left-hander Thomaz Bellucci 6-3, 6-4, 3-6, 7-6 (7-1) at Ashe Stadium.

The 29-year-old Wawrinka, this year's Australian Open champion, is through to the third round here for the fourth time in the past five years.

Up next for Wawrinka, who is from Switzerland, is Blaz Kavcic of Slovenia, who eliminated 30th-seeded Jeremy Chardy of France 6-2, 7-6 (8-6), 6-3.

Sixth seed Tomas Berdych was an easy opening-round winner. The big Czech and former Wimbledon runner-up blitzed 2001 U.S. Open champion and 2004 finalist Lleyton Hewitt 6-3, 6-4, 6-3 at Ashe Stadium. The fading 33-year-old Hewitt is also a former world No. 1.

Up next for Berdych will be Slovak Martin Klizan.

Grigor Dimitrov, the No. 7 seed, beat American Ryan Harrison 6-2, 7-6 (7-4), 6-2. It was Dimitrov's first win at the U.S. Open after three consecutive first-round exits dating back to 2011.

Eleventh seed Ernests Gulbis cruised past Frenchman Kenny De Schepper 6-1, 6-4, 6-2 to set up a second-round match with Dominic Thiem of Austria, who took down Lukas Lacko of Slovakia 6-3, 6-3, 6-2.

Portugal's Joao Sousa outlasted Canada's Frank Dancevic 7-6 (8-6), 3-6, 6-2, 4-6, 7-6 (7-2).

Meanwhile, 14th-seeded Croat Marin Cilic was leading former Australian Open runner-up Marcos Baghdatis 6-3, 3-1 when the Cypriot retired; 18th-seeded South African slugger Kevin Anderson outlasted Uruguay's Pablo Cuevas 6-3, 6-7 (3-7), 4-6, 6-2, 7-6 (7-1) in just over four hours; and 19th-seeded Spaniard Feliciano Lopez was tied with Ivan Dodig 1-6, 7-5, 2-6, 6-4, 1-1 when the hobbled Croat quit in the fifth set in round one.

A mild first-round upset came Russian Teymuraz Gabashvili topped 27th-seeded Colombian Santiago Giraldo 6-3, 1-6, 7-6 (8-6), 6-3.

American Steve Johnson had to retire from his first-round match against Tatsuma Ito of Japan because of severe cramping. Ito won by a 6-2, 3-6, 5-7, 4-1 score.

Meanwhile, David Goffin of Belgium beat fellow countryman Niels Desein 6-1, 6-3, 6-3 and Dudi Sela rallied past Carlos Berlocq 1-6, 6-3, 6-2, 7-5.

Also reaching the second round was 6-foot-8 Pole Jerzy Janowicz, a runner-up last week in Winston-Salem.