MLB.com's No. 3 prospect allowed an unearned run on five hits and struck out three over a season-high six innings as Triple-A Gwinnett fell to Buffalo, 4-3.
Teheran, who did not figure into the decision, ran into trouble in the third inning, allowing a leadoff single to Omar Quintanilla. Following a sacrifice bunt by pitcher Chris Schwinden, Teheran walked Bobby Scales and catcher J.C. Boscan allowed a passed ball to move Quintanilla over to third.
Dustin Martin's sacrifice fly scored Quintanilla, but Teheran avoided further damage by picking Scales off first.
"I was working on trying to have better command on every pitch and trying to throw a lot of strikes," Teheran said though translator Ernesto Mejia. "I threw a lot of strikes and that helped out a lot. I was mixing pitches, offspeed and my fastball. I was feeling really good."
In his last two starts, the 21-year-old right-hander has yielded five runs on nine hits over 7 1/3 innings. Teheran, who threw 55 of his 90 pitches for strikes, was pleased to go as deep as he did Monday, but felt he had more.
"I always try to throw as far as I can, at least six or seven innings," Teheran said. "Tonight I was happy. I was ready to keep going, I was feeling really good."
Although he didn't pick up his third win, Teheran was satisfied with his outing.
"It's not too important for me right," he said. "The only thing I'm worried about is having a good game and having command of my pitches. If I don't get the win, it's OK."
Mejia provided some offense in support of Teheran's outing, going 2-for-5 with an RBI. Stefan Gartrell slugged a solo homer and Jose Constanzo had three hits and scored twice.
Jay Chapman (1-2) took the loss for the Braves after allowing a run on one hit and walking two while only retiring one batter.
Rob Johnson hit a two-RBI single in the eighth to put the Bisons ahead for good.