Milos Raonic won the final set after an overnight break to beat Nick Kyrgios of Australia 6-7 (5), 6-4, 6-4 Wednesday at the grass-court Queen's Club.
Resuming the match on one set each after poor light ended play Tuesday, the third-seeded Canadian won the decider to advance to the second round.
Playing his first tournament under the guidance of three-time Wimbledon champion John McEnroe, Raonic broke to lead 5-4 when his opponent double-faulted but had to fight off two break points as he served for the match.
Also in the first round, British wild card Kyle Edmund defeated eighth-seeded Gilles Simon of France 6-4, 3-6, 6-1. Paul-Henri Mathieu of France was also stretched to three sets before overcoming Daniel Evans of Britain 7-6 (8), 6-7 (6), 6-3.