Wawrinka erased all four break points to beat former world No. 7 Fernando Verdasco, 7-6, 6-4, 6-4.
“I knew it would be a difficult match,” Wawrinka said on court after the win. “First one, it’s never easy… I’m really happy to have won… It’s a really good result for me.”
Nishikori advanced to second round after winning the match over 35 year old Becker, 6-1, 6-1, 3-6, 6-3. No. 142 seed Del Potro secure his second round match with a win over 24 year old Schwartzman 6-4, 6-4, 7-6.
Ferrer, Lopez, Vesnina, V, Williams, Carla Suarez-Navarro and S. Halep also advanced to the second round.
Tomic stunned by no. 72 seed Dzumhur with 6-4, 6-3, 4-6, 7-6. 24 year old player has retaliated for the last year’s loss at US Open. Bouchard is also out of the tournament after having suffered loss from Siniakova in her first-ever US Open victory 6-3, 3-6, 6-2, in the first round. The former No. 1 Ana Ivanovic, didn’t make it to the second round. She had loss 7-6, 6-1 from 89th-ranked Denisa Allertova.