How about one more match? That, at least, is a given now.

Roddick’s not quite ready to quit just yet.

A day after surprisingly announcing the US Open will be the last tournament of his career, Roddick dominated Australian teenager Bernard Tomic from start to finish Friday night in Arthur Ashe Stadium and won, 6-3, 6-4, 6-0, to reach the third round.

‘‘I had no idea what was going to happen out there,’’ Roddick said. ‘‘I've played a lot of matches and that was a different kind of nerves than I've had before, so that was surprising for me.’’

The 2003 US Open champion and former No. 1-ranked player took the time to look around the packed arena, eyeing people dancing in the stands during changeovers and taking it all in — in case this was it.

Roddick, who turned 30 on Thursday, and held a news conference to say he would quit after a season of injuries and poor results at Grand Slam tournaments. But he sure looked good against the 43d-ranked Tomic, hitting 13 aces, including the final point.

Not only was Tomic outclassed, but by the late stages, TV commentator and seven-time major champion John McEnroe was telling ESPN2 viewers that the Australian maybe should be fined for lack of effort.

Other men’s winners Friday included defending champion Novak Djokovic, 2009 champion Juan Martin del Potro, and 2001 champion Lleyton Hewitt, who came back to beat Gilles Muller 3-6, 7-6 (7-5), 6-7 (5-7), 7-5, 6-4.

The day’s biggest surprise was 18-year-old Laura Robson’s 6-4, 6-7 (5-7), 6-2 victory over 2011 French Open champion Li Na, setting up a fourth-round match against defending women’s champion Sam Stosur. Robson ended four-time major champion Kim Clijsters’s singles career by beating her in the second round.