Four-time champion Roger Federer crushed Alex Bogomolov, of Russia, 6-3, 6-2, leading the world's best players into the third round of the Cincinnati Masters.
World number one Federer -- who has reached the semi-finals or better at 11 of the last 12 ATP events he has played -- was untouchable in his first outing since the Olympics, and will now face Australia's Bernard Tomic.
Federer won the trophy here in 2005, 2007, 2009 and 2010 and is bidding for some personal Masters 1000 history as he chases a fifth title.
The match lasted just an hour as Federer dominated, though he did need two match points and faced -- and saved -- his only break point of the match in the final moments of play.
"It was a good match for me," said the 17-time grand slam champion. "I don't know his game that well, but we played a good match. The switch from grass to hardcourt is difficult.
"This court is faster than Wimbledon and the bounce is really high. It may have gone quickly and there were hardly any rallies, but I was pleased to close it out."
Second seed Novak Djokovic made a scratchy start while Andy Murray motored through as the pair of seeds won their opening matches after first round byes.
Djokovic did not even have the chance to hit on the showcase court after arriving in the midwest US from his post-Olympic title in Toronto at the weekend.
The Serb defeated Italian Andreas Seppi 7-6 (7/4), 6-2, but he was not impressed with his form, dubbing the win "not a great performance," though he improves to a 9-0 record over Seppi, whom he struggled with at Roland Garros in a comeback from two sets down in the fourth round.
"I didn't do anything special out there. I was just trying to get used to conditions, trying to keep the ball on the court and hit one more than my opponent," Djokovic said.
"This happens in every first match, you have to get used to quite different conditions. I came in late from Canada and it feels a lot different here."
Djokovic won in just under 90 minutes, a contest which included a 59-minute opening set in which the second seed needed four set points to take the lead.
But the Serb stepped it up in the second as he ran out the winner with 21 winners against 22 unforced errors.
Djokovic will line up in the third round against Russian veteran Nikolay Davydenko, who beat Florian Mayer of Germany 6-3, 6-3.
Murray, the Olympic gold medalist who played one match last week in Toronto and then quit with a sore knee, showed no sign of injury as he knocked out American Sam Querrey 6-2, 6-4, in just 83 minutes.
"It felt fine," Murray said of his knee. "I moved well today. It was still giving me a little bit of trouble in practice for a couple of days before the tournament, but it felt much, much better. I'm hoping it won't be a problem."
Federer's fellow Swiss Stanislas Wawrinka upset fourth seed David Ferrer 6-4, 6-1.
Argentine sixth seed and former US Open winner Juan Martin del Potro knocked out Germany's Tommy Haas 7-5, 6-2, But Czech Radek Stepanek returned the favor with his defeat of Argentina's eighth seed Juan Monaco 7-6 (7/2), 6-1.
Mardy Fish, the US 10th seed, beat Argentine Carlos Berlocq 6-3, 6-1.
Croatian 12th seed Marin Cilic put out Jesse Levine 7-5, 7-6 (8/6) and Australian wild card Lleyton Hewitt went down to Serb Viktor Troicki 6-2, 6-0 after not getting to bed until 3 a.m. in his Monday late-night opening win.
In the women's second round, top seed Agnieszka Radwanska dispatched Swede Sofia Arvidsson 6-4, 6-3.
Fourth seed Petra Kvitova defeated German Mona Barthel 3-6, 6-2, 7-5 while number six Caroline Wozniacki hammered Sesil Karatantcheva 6-1, 6-0.
Italy's seventh seed and Roland Garros finalist Sara Errani beat Slovak Daniela Hantuchova 6-4, 6-4.