Hefner let up a two-run home run in the first, but then retired 16 of the final 18 batters he faced.
LaTroy Hawkins quickly surrendered a home run to Dan Uggla that tied the game to start the seventh inning.
"I was so excited that he pitched so well after he's been so down about not winning a game. I said, 'I'm not going to let this kid lose this game. I'm not going to do that,'" Collins said, acknowledging that Hefner felt good enough to keep pitching. "He needs to move forward with a positive attitude that he pitched very, very well. Even though he did pitch well, had something happened the next inning, he goes home feeling bad about it. And I didn't want that to happen."