After a disastrous fifth inning spoiled his day, Teheran promised he'll be better prepared for his next opportunity with the Braves.
Teheran and Livan Hernandez couldn't hold an early four-run lead as the Toronto Blue Jays scored six runs in the fifth and beat Atlanta 12-4 on Sunday.
Teheran, the Braves' top prospect, was called up from Triple-A Gwinnett to fill in for Tim Hudson, who has bone spurs in his left ankle. Relying on his curveball, Teheran allowed only one hit, Edwin Encarnacion's broken-bat single, through four scoreless innings before wilting in the fifth.
"I got a little bit too excited because I wanted to win the game," Teheran said. "I got a little out of control.
"I'll try to be better for the next one."
Teheran gave up four hits and four runs in 4 1-3 innings before returning to Gwinnett, where he is 5-2 with a 3.15 ERA in 11 starts.
Manager Fredi Gonzalez said Teheran was told this would be a one-game visit to Atlanta, no matter how he fared.
"The first four innings, obviously, he's nails," Gonzalez said. "And then one of those hurdles in the fifth. ... Young kid, sometimes that kind of throws him out of whack.
"But I thought the first four innings were as impressive as I've seen him, a good mixture of fastballs and curveballs and getting everything over for a strike. That fifth inning kind of got away from us a little bit."
Brett Lawrie and Colby Rasmus each homered and drove in three runs as the Blue Jays set a season high with 18 hits.
Gonzalez said the loss "might be the ugliest game we've played in a long time."
The Blue Jays ended their three-game losing streak and Atlanta's season-best six-game winning streak.
"The way things started out, it wasn't looking real promising," Blue Jays manager John Farrell said. "We were able to string a number of hits together. ... We were able to string together not only the six runs but it continued on through the middle and latter part of the game."
Blue Jays left-hander Ricky Romero lasted only four innings. He gave up eight hits and four runs, three earned.
A key to the Blue Jays' six-run fifth was Farrell's decision to replace Romero with pinch-hitter Yan Gomes, whose single drove in the first run and knocked Teheran out of the game. It was the first of five straight run-scoring hits.
Lawrie hit a two-run homer and Rasmus added a homer off Hernandez as Toronto added three runs in the sixth.
Carlos Villanueva (1-0) pitched two scoreless innings.
Hernandez (1-1) gave up five runs on seven hits, including two homers, in 1 2-3 innings. Hernandez has allowed nine earned runs on 13 hits in 4 2-3 innings in his last two appearances.
Kelly Johnson singled to start the fifth. Yunel Escobar walked and, after David Cooper struck out, J.P. Arencibia singled to load the bases in the fifth. Gomes' single, which ended 0-for-16 slump, knocked Teheran out of the game.
Hernandez quickly inspired boos from the rain-drenched fans by giving up four straight hits: a single by Lawrie to drive in a run, a two-run single by Rasmus, a run-scoring single by Jose Bautista and Encarnacion's two-run double, giving the Blue Jays a 6-4 lead.
The boos grew louder in the sixth when Hernandez was left on the mound to endure another barrage that included the two-run homer by Lawrie, his fifth, followed by Rasmus' eighth homer.
Gonzalez said he stuck with Hernandez because he thought the right-hander's experience would enable him to recover.
"He's not going to spook in that situation," Gonzalez said. "And they got him. Got to tip your cap to the Toronto Blue Jays."
Rajai Davis singled in a run and pinch-hitter Omar Vizquel drove in a run with a sacrifice fly off Cristhian Martinez in the seventh. Kelly Johnson had triple off Martinez to drive in a run in the eighth.
Chipper Jones came off the disabled list and was 0-for-3 with a walk. Juan Francisco replaced Jones in the seventh.
Dan Uggla was hit by a pitch from Romero to open the second. Uggla moved to third on a double by Matt Diaz and scored when Rasmus dropped the ball for an error after making the catch on Freddie Freeman's fly ball.
David Ross had a run-scoring single in the second and Freddie Freeman drove in a run with a single in the third for Atlanta. Freeman had three hits.
Uggla had played every inning this season before he was replaced by Jack Wilson to open the eighth.
Bautista and Rasmus made back-to-back diving catches of drives by Michael Bourn and Martin Prado in the eighth.
NOTES: The 18 hits are the most for Toronto since they had 20 at Baltimore on Aug. 31, 2011. ... The Braves optioned C J.C. Boscan and OF Jose Constanza to Triple-A Gwinnett to clear roster spots for Teheran and Jones. RHP Cory Gearrin will be recalled from Gwinnett, replacing Teheran, to pitch out of the bullpen. ... Lawrie's RBI single in the fifth snapped an 0-for-17 drought. ... Hudson said his ankle feels better and he should be ready to start on Wednesday against the Yankees. ... Randall Delgado will face Ivan Nova in a matchup of right-handers when the Braves open a three-game home series against the Yankees on Monday night. The Blue Jays play another NL East team as they return home to open a series against Washington on Monday night with RHP Brandon Morrow trying for his eighth win.