Delgado allowed just one run on three hits. He walked three and threw 93 pitches.
"The first couple innings, I was a little uncomfortable," he said. "But I made a few adjustments and it wasn't too bad."
Delgado was in line for his first Major League win. He left with a 2-1 lead and the Braves carried a 3-1 cushion into the bottom of the ninth before closer Craig Kimbrel blew his first save since June 8.
"He competed," Atlanta manager Fredi Gonzalez said of Delgado. "If you had to critique him really hard, 100 or so pitches in five innings is a lot of work."
Gonzales was impressed enough to give Delgado another shot. The native of Panama will make his fifth start Wednesday afternoon against Florida.
Gonzalez also announced that rookie Julio Teheran will go to the bullpen. Teheran picked up his first win in a 5-1 triumph over the Mets on Thursday.