Murray, who secured titles in 2009, 2010 and 2015, saved two set points and clinched the first set against Sonego in a 90-minute battle. The three-time Grand Slam champion then swiftly dominated the second set against the Italian.
Murray is set to face Australia’s Max Purcell.
Purcell defeated Canada’s Felix Auger-Aliassime lost 6-4, 6-4. Purcell, who entered the tournament as a qualifier, had eight aces to just one double fault. He also broke on two of his four chances.
The Aussie defeated Canadians Peter Polansky and Brayden Schnur – both in straight sets – to make it into the main draw.
Canada’s Gabriel Diallo won his first ATP Tour level match, defeating Great Britain’s Dan Evans 7-6 (4), 7-5 to advance to the second round. The Montreal native never fell behind in the match, although he went through a back and forth first set that saw him consistently have to keep Evans at bay. He picked up set point on an Evans double fault. Diallo will face Australia’s Alex de Minaur in the second round. The Aussie defeated 11th-seeded Brit Cameron Norrie 7-5, 6-4 earlier Tuesday.
Earlier in the day, American Sebastian Korda easily dispatched the Argentine Tomas Martin Etcheverry 6-3, 6-2.
In first-round men’s doubles action, Vasek Pospisil of Vernon, British Columbia, and partner Nicolas Mahut of France defeated Canadians Kelsey Stevenson and Benjamin Sigouin 7-5, 6-4 to advance.
The Canadian pairing of Adil Shamasdin and Peter Polansky were also bounced, falling 6-3, 6-2 to Germany’s Tim Putz and Kevin Krawietz.