Second-seeded Milos Raonic was made to work for a 6-7 (5), 6-1, 7-5 victory over qualifier Andrey Kuznetsov and a place in the second round of the World Tennis Tournament.
Coming off an Australian Open quarter-finals loss, Raonic hit 19 aces to rally past the 23-year-old Russian in a contest lasting nearly two hours. Raonic got off to a sluggish start but managed to claw his way back with his big serve
The Canadian, who will take on Simone Bolelli in the next round, lost only six points on his first serve.
Eighth-seeded Gilles Simon defeated Joao Sousa 5-7, 6-3, 6-2 and Vasek Pospisil converted three of his four break points in a 6-4, 6-2 victory over Philip Kohlschreiber.
Meanwhile, Lleyton Hewitt will begin his preparations for his final bow at Wimbledon this year at the Aegon Championships after organisers of the Queen's Club grasscourt event guaranteed the Australian a wildcard.