Top seed Fernando Verdasco eased into the third round of the New Haven ATP event on Monday with a 6-4 6-4 win over Israeli Dudi Sela.
The Spaniard, who had a first round bye, was too good for the world number 75 as he clinched victory in one hour, 19 minutes.
Verdasco will play either 15th seed Eduardo Schwank or Czech Ivo Minar for a place in the quarter-finals.
American wildcard entries John Isner and Robby Ginepri advanced to the second round.
The 6ft 9in Isner won 6-4 6-4 against Russian Igor Kunitsyn, a semi-finalist last week in Washington. His reward is a second-round clash with second seed Ivo Karlovic, the tallest player on the tour at 6ft 10in.
Isner and Croatian Karlovic joined forces to play in the doubles at the Australian Open this year, making the tallest combination in tennis.
"That will be interesting for sure," Isner said. "If I somehow play well enough to win, that will be huge."
Former U.S. Open semi-finalist Ginepri saw off Peruvian Luis Horna 7-6 6-2 to set up a second-round clash with 12th seed Agustin Calleri of Argentina.
Among other men to advance to round two were Viktor Troicki of Serbia and former Australian Open runner-up Arnaud Clement.
Troicki, runner-up to Juan Martin Del Potro in Washington on Sunday, recovered quickly to beat American qualifier Alex Bogomolov Jr. 7-5 2-6 6-1.
Exhausted winner
Argentine Del Potro pulled out of the event citing exhaustion after winning back-to-back titles in Los Angeles and Washington.
"It is difficult to still play a lot of matches," Del Potro, who is on a 19-match winning streak, told reporters.
"I want to recover for the US Open. Unfortunately I have to pull out of this tournament."
Frenchman Clement was too strong for Thomaz Bellucci of Brazil, winning 6-4 6-4.
In the women's event, fifth seed Patty Schnyder, who took a wildcard entry after playing at the Olympics last week, survived a tough battle with American Jill Craybas to win 6-4 7-6.
Seventh seed Alize Cornet of France edged out Czech Nicole Vaidisova 6-3 7-6 in the first round but eighth seed Dominika Cubulkova of Slovakia retired after losing the first set to Dane Caroline Wozniacki because of illness.
Australian Casey Dellacqua set up a clash with top seed Ana Chakvetadze of Russia after beating France's Virginie Razzano 6-3 6-1.
