The left-hander doubled home two runs in the sixth inning Sunday to give the Reds the lead, and Cincinnati hung on for a 5-4 win over Pittsburgh.
The victory was the first for Willis (1-6) as a Red.
He went six innings and allowed three runs on three hits. He walked two and struck out six. Other than the third -- when he allowed the three runs and two of the hits -- he was dominant. In the other five innings, Willis faced one over the minimum 15 batters.
And there was the big double.
"That's Dontrelle," Reds manager Dusty Baker said. "He's always going to do that. He wanted it very badly ... It was great to get him that first one. It was a long time coming."
It was 13th start of the year for the Reds. Most have been good. But he allowed eight runs in 3 1/3 innings his last time out.
"The guys battled for me," Willis said. "They knew it was my last start. The way I pitched poorly (in my) last start, I really wanted to finish the season with confidence."
After allowing three in the third, Willis only allowed one hit the rest of the way.