Roger Federer returned from a month-long layoff with a 6-4, 6-4 second round victory over Roberto Bautista Agut on Tuesday at the Western and Southern Open in Cincinnati.
Federer had not competed since losing in the Wimbledon final to Novak Djokovic and he quickly shook off the rust, needing just an hour and nine minutes to beat Agut.
"It's the first round of the hard court season for the next six plus months or so," Federer told the ATP Tour website after his first match at the tournament having received a bye into the second round.
"I have things in mind to work on for the hard-court season. Number one, you have to be fit and tough, because you can stop on a dime and move the other direction, which on other surfaces is not so easy to do."
Earlier, controversial Australian Nick Kyrgios, who hit the headlines last week when he taunted opponent Stanislas Wawrinka in Montreal, was crushed 6-2, 6-1 by Richard Gasquet in their first round match.
Kyrgios appeared distracted for much of a one-sided contest and summoned the trainer for treatment on his back before he was swept aside in just under an hour.
Gasquet, the 12th seed, converted four of his six break points before sealing victory with his fourth ace of the match and will next face 19-year-old Australian Thanasi Kokkinakis, who was an integral part of Kyrgios's taunts last week.
Kyrgios, 20, drew the ire of the tennis world in Montreal after he insulted Wawrinka during a match at the Rogers Cup, saying that Kokkinakis had slept with the Swiss player's girlfriend.
Though Kyrgios later apologised via Twitter for his comments, he was slapped with two separate fines by the ATP who also raised the possibility he could be suspended.
Federer had also been critical of Kyrgios' behaviour.
"He definitely crossed the line by a long shot," Federer told the Cincinnati Enquirer.
"We're not used to that kind of talk in tennis. It's normal that the tour comes down hard on him and explains to him that it's not the way forward."
Federer also described the controversy as 'not great for the sport', saying that many players have tried to build up and make it a good image.
In other matches on Tuesday, Sam Querrey beat fellow American John Isner 6-3 7-6(3) in a first round match-up of big servers and Croatian Borna Coric scraped past Alexander Zverev of Germany 7-5, 3-6, 7-6(5).
"I thought I played well," said Querrey who will next face Spaniard Tommy Robredo, a 3-6, 6-3, 6-1 winner against fellow Spaniard Pablo Andujar.
"Returned well. Did everything. Forehand and backhand were solid. Didn't make many mistakes. I was happy how I played."
Spaniard left-hander Fernando Verdasco came from a set down to battle past Jo-Wilfried Tsonga 4-6, 6-3, 6-4 after two hours and 15 minutes.
Maria Sharapova and Venus Williams were big-name withdrawals from the Western and Southern Open in Cincinnati on Tuesday as they attempt to fully recover from injury and illness ahead of the US Open.
Russian second seed Sharapova, who has yet to play since a semi-final defeat at Wimbledon last month, cited a leg injury for her exit.
"It's a tough decision to make but I think it's the right decision to be ready for the US Open," Sharapova told reporters.
"It's not ideal preparation for New York, but that's the circumstance and I obviously want to give myself the best chance to be healthy there. That's the wisest move right now."
Williams was forced to pull out due to a viral illness, something that had bothered her in Monday's victory over Zarina Diyas, denying fans an attractive second round encounter between the American and former No 1 Ana Ivanovic.
"(It would) have been a tough match for both of us," Serbia's Ivanovic tweeted.
"I hope she can get well fast."
The US Open begins on August 31.
On the court, Swiss prospect Belinda Bencic continued her brilliant run of form with a 7-5, 6-3 first-round victory over Germany's Angelique Kerber.
Bencic, who shocked world number one Serena Williams in the semi-finals of last week's Rogers Cup before going on to clinch the title, fended off attempted comebacks by the 11th-seeded Kerber in both sets before sealing victory in 90 minutes.
Though Kerber clawed back from 5-1 down in the opening set and 3-1 in the second, she ultimately paid the price for a whopping 48 unforced errors and seven double faults.
"The first set was a very difficult situation," said the 18-year-old Bencic, who converted six of her seven break point opportunities during the match.
"I had 5-1 and I was playing great but then she played better and better and started going for her shots more until it was five-all again.
"But then I was able to focus again and won my service game, and then I closed it out."
Bencic will next face Italy's Flavia Pennetta, who beat Dominika Cibulkova of Slovakia 7-5 6-2 in the opening round.
In other matches, 10th-seeded Spaniard Carla Suarez Navarro was ousted 6-1 6-2 by American Sloane Stephens, while former world number one Victoria Azarenka of Belarus trounced American Lauren Davis by the same scoreline.