The No. 16 seed needed only 63 minutes to see off the world No. 38', winning 6-2 6-3 in Montreal on Wednesday.
The Australian, 22, bullied Lorenzi with his serve, firing 10 aces to one and winning 96 percent of points on first serve.
He wrapped up the first set in 29 minutes after breaking his opponent twice, and claimed a decisive break in the fourth game of the second.
The results continues Kyrgios' good form at the tournament.
He beat Viktor Troicki in 51 minutes in the first round, appearing to have overcome the hip and shoulder problems that had forced him retire in Washington last week and at Wimbledon in July.