Hernandez was promoted Friday after third baseman Josh Donaldson went on the disabled list with right shoulder inflammation.
Hernandez also hit an RBI double in a three-run ninth inning in which Steve Pearce had a two-run double against Indians reliever Matt Belisle.
The Blue Jays (9-5) overcame a 4-0 disadvantage to tie the game at 4 on a three-run homer by Aledmys Diaz in the fourth inning.
The loss stopped a five-game winning streak by the Indians (8-6), who are 6-2 at home.
Cleveland scored twice in the first against right-hander Marcus Stroman on RBI singles by Yonder Alonso and Tyler Naquin and two more in the second on RBI doubles from Francisco Lindor and Jason Kipnis.
Diaz's fourth homer of the season keyed a four-run fourth against Indians starter Mike Clevinger that tied the game. Justin Smoak and Yangervis Solarte worked one-out walks to start the rally, and Kevin Pillar had an RBI single.
Clevinger allowed three hits, two walks and four runs while striking out five in four innings.
Danny Barnes (1-0) took over in the sixth for Stroman, who allowed nine hits, two walks and four runs with five strikeouts. Barnes allowed a double to Lindor, who was thrown out at home by second baseman Devon Travis on an infield single by Jose Ramirez.
Zach McAllister (0-2) entered the game in the seventh for Cleveland, replacing Dan Otero, who pitched two clean innings. Randal Grichuk worked a leadoff walk, stole second and took third on a groundout by Travis.
Andrew Miller replaced McAllister. Grichuk was out at home on pinch hitter Pearce's groundout to first. Pearce took second on a passed ball and scored on Hernandez's double to left.
Toronto closer Roberto Osuna pitched the ninth in a non-save situation and retired the side in order with two strikeouts.
--Field Level Media
Toronto | Cleveland | |
Marcus Stroman | Player | Mike Clevinger |
No Decision | W/L | No Decision |
5.0 | IP | 4.0 |
5 | Strikeouts | 5 |
9 | Hits | 3 |
7.20 | ERA | 9.00 |
Toronto | Cleveland | |
Aledmys Diaz | Player | Francisco Lindor |
2 | Hits | 3 |
3 | RBI | 1 |
1 | HR | 0 |
5 | TB | 5 |
.500 | Avg | .600 |