Three-time Grand Slam champion Stan Wawrinka made light work of Britain's Cameron Norrie in the opening round of the Queen's Club grasscourt tournament on Monday, winning 6-2 6-3.
The 33-year-old Swiss, ranked 261 in the world after two knee surgeries, served solidly throughout a one-sided contest on the slick centre court, easing past an opponent who struggled to cope with Wawrinka's power.
Wawrinka needed just shy of half an hour to pocket the opener, breaking twice, and was hardly troubled in the second set as he set up a second round against American fifth seed Sam Querrey or young British wildcard Jay Clarke.
"In general (the knee) has been improving week after week," Wawrinka, beaten in the first round of the French Open, said on court. "Now I feel really good on court, strong physically.
"I will have ups and downs in the next months and need to be patient. You need to be ready to accept frustrating but today was a great day."
Luxembourg's Gilles Muller, the man who ended Rafael Nadal's run at Wimbledon last year after reaching the Queen's semi-final, had earlier knocked out exciting Canadian shot-maker Denis Shapovalov in two tiebreaks.
Top seed Marin Cilic of Croatia was in action later against Spain's Fernando Verdasco.
Double Wimbledon champion Andy Murray makes his return after nearly a year out with a hip injury on Tuesday when he will face Australian Nick Kyrgios in the first round.
Rybarikova stuns Pliskova in Birmingham opener
World number seven Karolina Pliskova's Wimbledon preparations suffered a setback in a 6-2 6-3 defeat by Magdalena Rybarikova of Slovakia in the opening round of the Nature Valley Classic in Birmingham on Monday.
The 29-year-old Rybarikova, who ended Pliskova's Wimbledon campaign last year in a three-set thriller, was in complete control from the start as she claimed the victory in just over an hour.
"Karolina is a great player, and I have a lot of respect for her," Rybarikova, the 2009 winner in Birmingham, said courtside.
"Today I don't think it was her best day, but it was all about serves and returns and I was just better at that. That was the key.
"I put so many returns in, and maybe she was thinking about our last match in Wimbledon. It could have been a different result today, but I'm so happy that I won this match."
Rybarikova will face Kristina Mladenovic for a place in the quarter-finals after the Frenchwoman edged past Czech Katerina Siniakova 1-6, 6-2, 6-4.
Austria's Thiem races past Youzhny in Halle opener
French Open runner-up Dominic Thiem began his grasscourt season with a convincing 7-6 (5), 6-2 victory over Russian Mikhail Youzhny in the opening round of the Halle Open on Monday.
Thiem, seeded third, failed to serve out the opening set at 5-4 but won the final three points in the tiebreak, before taking control of the match in the second set.
The 24-year-old Austrian finished with 19 aces and converted three break points to collect his 36th match win of the season.
Thiem is set to make his fifth consecutive appearance at Wimbledon next month but has never got beyond the fourth round.
However, he will be looking to improve that record on the back of his maiden Grand Slam final appearance at Roland Garros.
Thiem will next face Japan's Yuichi Sugita, who beat German wildcard Maximilian Marterer 6-4, 5-7, 6-3.