Houston - Serbia's Janko Tipsarevic made a triumphant return to the ATP Tour on Tuesday, saving two match points en route to win over Guilherme Clezar in his first match in 17 months.
Tipsarevic, once ranked as high as eighth in the world, has been sidelined after multiple surgeries on his left foot.
But he showed no sign of any lingering effects of the injury as he defeated 186th-ranked Brazilian qualifier Clezar 6-4, 3-6, 7-6 (9/7) to reach the second round of the clay-court tournament in Houston.
"In my mind, I don't feel like I was away for so long," Tipsarevic said.
"I felt like this was a match I needed to win. I was ready, and I was fit. I had no confidence coming in, but saving match points with forehand winners down the line maybe proved otherwise.
"I really felt I had to win this match, and I would have been really sad otherwise."
Tipsarevic laid down 18 aces and converted four of his seven break chances.
It was his first match since he retired against Marcel Granollers in the first round at Valencia in October 2013.
"I'm in pain everywhere, but the foot is good," he laughed after wrapping up the victory in a tough two hours and 38 minutes.
Spain's Feliciano Lopez is the top seed in the tournament.
After a first-round bye, Lopez will take on American Sam Groth in his second-round opener on Wednesday.
In other first-round matches on Tuesday, fifth-seeded Colombian Santiago Giraldo defeated Rogerio Dutra Silva of Brazil 6-2, 6-2.
Defending champion Fernando Verdasco of Spain, the sixth seed, defeated Paolo Lorenzi when the Italian retired injured while trailing 6-3, 4-3.
Seventh seventh-seeded Frenchman Jeremy Chardy reached the second round, dispatching Serbia's Dusan Lajovic 6-4, 6-4.Results from the second day of the ATP Houston Open on Tuesday (x denotes seeding):
Steve Johnson (USA) bt Donald Young (USA) 7-5, 6-4
Teimuraz Gabashvili (RUS) bt Tim Smyczek (USA) 6-3, 6-3
Chung Hyeon (KOR) bt Facundo Arguello (ARG) 6-3, 7-5
Fernando Verdasco (ESP x6) bt Paolo Lorenzi (ITA) 6-3, 4-3 - retired
Jeremy Chardy (FRA x7) bt Dusan Lajovic (SRB) 6-4, 6-4
Santiago Giraldo (COL x5) bt Rogrio Dutra Silva (BRA) 6-2, 6-2
Janko Tipsarevic (SRB) bt Guilherme Clezar (BRA) 6-4, 3-6, 7-6 (9/7)
Jack Sock (USA) bt Joao Souza (BRA) 5-7, 6-4, 6-2