Whit Merrifield and George Springer finished with three hits each and Kevin Kiermaier had two hits for Toronto (74-61), which moved within 1 1/2 games of Texas for the final AL wild-card berth.
Nolan Jones homered among his three hits, Elehuris Montero also homered and had two hits while Ezequiel Tovar and Ryan McMahon had two hits apiece for Colorado. The Rockies (49-85) have lost four straight.
Colorado got on the board in the third inning against Blue Jays starter Hyun Jin Ryu on Montero's two-run homer, his sixth of the season.
Belt led off the fourth with his 16th homer and Clement tied it an inning later with a leadoff homer, his first of the season.
The Blue Jays went ahead in the sixth inning when Belt singled with one out and Jansen followed with his 17th home run of the season to make it 4-2. Dalton Varsho walked with two outs to end starter Chris Flexen's night.
Flexen allowed four runs on seven hits in 5 2/3 innings.
Yimi Garcia relieved Ryu, who allowed two runs on four hits in five innings, to start the sixth and Colorado rallied.
Elias Diaz reached on an error and McMahon singled but Garcia struck out the next two batters. Genesis Cabrera (3-1) relieved Garcia and Jones homered to left to put the Rockies ahead 5-4.
Toronto answered in the seventh on Davis Schneider's RBI double off Jake Bird (2-2) and Alejandro Kirk's three-run double off Brent Suter.
Merrifield then doubled to right-center field to drive in Kirk.
The Blue Jays added another run in the eighth on Vladimir Guerrero Jr.'s double to left and padded the lead on Clement's two-run triple in the ninth along with Springer's RBI single.
Jones led off the ninth with a triple and scored on Montero's single. Brenton Doyle doubled, Montero scored on a groundout and Doyle came home on a single by Diaz.
Diaz scored on McMahon's double before the Rockies' four-run ninth came to an end on a strikeout by Brendan Rodgers.
—Field Level Media