Murray, seeded second at this Masters Series event, lost in the third round in Montreal a week ago to Ernests Gulbis.
He received a bye past the first round of this event and got back on the winning track with a 6-2, 6-3 decision over Mikhail Youzhny. Last week's loss ended a 12-match winning streak that included his triumph at Wimbledon.
Djokovic was a 7-5, 6-2 winner over Juan Monaco and will now take on David Goffin, who outlasted Vasek Pospisil 7-5, 1-6, 7-6 (8-6). Djokovic has reached the final of this tournament four times without winning the championship.
Nadal breezed past Benjamin Becker 6-2, 6-2. Grigor Dimitrov will now take on Nadal after defeating Brian Baker 6-3, 6-2.