The big-serving Canadian hit 14 aces and never faced a break point, as he cruised past Leonardo Mayer 6-3 6-2 6-3 in an hour and 49 minutes. The Cincinnati finalist continued his impressive form, hitting 42 winners while committing 33 unforced errors. Furthermore, he employed improved volleying that saw him win 85% of points when he approached the net.

Raonic dictated play from the baseline and closed out easy points at the net, giving Mayer little chance to mount a comeback. He next faces compatriot Vasek Pospisil, who defeated German veteran Philipp Kohlschreiber 7-6(4) 7-5 7-6(3) in his first round match.

Bulgarian Grigor Dimitrov also got off to a winning start, defeating American Tommy Paul 6-4 6-3 6-1 to advance to the second round. The 14th seed won 84% of his first serves, and saved all seven break points faced. His consistent play from the baseline frustrated Paul, who committed 38 unforced errors while hitting only 13 winners. Dimitrov will face Marton Fucsovics in the second round, as the Hungarian defeated Hugo Dellien 6-3 6-3 6-1 earlier in the day.

In an earlier match, eighth seed Roberto Bautista-Agut booked his spot in the second round, with an academic 6-4 6-4 7-6(3) win over American Tennys Sandgren.

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