Sam Querrey began the defence of his Queen's title in comfortable fashion with a 6-3 6-4 win over Kei Nishikori.
The American's serve dictated and despite late fireworks from the Japanese star, Querrey, ranked 26, soon set up a clash with Rainer Schuettler.
Feliciano Lopez will play four-time champion Andy Roddick after beating Dmitry Tursunov 7-6 (7-4) 6-3.
While Andy Murray awaits a late fitness test, British wildcard Oli Golding, 17, lost 6-3 6-4 to France's Nicolas Mahut.
Murray, one of eight seeds to get a bye, is scheduled to play Xavier Malisse of Belgium or German world number 99 Matthias Bachinger.
Having practised on Monday afternoon, he will decide later whether to risk his injured ankle.
The British number one, who lost to Rafael Nadal in the French Open semi-final, sustained a partial tear to a ligament in his right ankle during his third-round meeting with Michael Berrer at Roland Garros.
On the opening day at Queen's, there were three Britons in action. James Ward defeated compatriot Daniel Cox 6-3 6-1 to set up a second-round tie against Swiss fourth seed Stanislas Wawrinka.
Meanwhile there was a hugely encouraging show from Golding on his his Queen's debut.
The 17-year-old was outclassed by the man who was defeated by American John Isner 70-68 in the deciding set of the marathon first-round encounter at Wimbledon last year.
But the teenage junior showed plenty of promise and looked far from over-awed in front of a large appreciative crowd in London and playing the biggest match of his career.
"It was unbelievable," Golding told BBC Sport. "The crowd were great and I enjoyed every second of it and has given me the desire to come back year after year.
"I played within myself but then later on I gave it everything. I've taken a lot of confidence from it and has shown that I'm not far from this level. I've now just got to go out and work hard."
Mahut, ranked 103 in the world, suggested Golding needed time to learn, but complimented his groundstrokes, backhand and first serve.
"He's a good talent. If he keeps working hard, he will be a very good player," the French 29-year-old said.
"First-ound games are never easy and I'm pleased to make the second round."
Mahut will next play Spanish seventh seed Fernando Verdasco.
Rafael Nadal, having won a sixth French Open on Sunday, heads the field in the opening event of the grass-court season for the men but world number two Novak Djokovic was forced to pull out last week with a niggling knee injury.