With two outs in the fourth inning and two on, Hanigan sent a 2-1 curveball from James Shields over the fence in left field. It was his first homer since he hit two on April 3.
"I was trying to relax and get some pitches I could handle. He's tough," Hanigan said. "He changes speeds and he's a tough guy to sit on pitches with, because he's got four quality pitches. I was seeing the ball. He threw one up in the zone, and I was back on it, and I put a good swing on it."
Ramon Hernandez had caught the last three games, and Reds manager Dusty Baker had hoped Hanigan would be ready for the finale of the road trip.
"It's perfect timing, because it's day after night, we have an off-day tomorrow," Baker said.
Hernandez usually catches Reds starter Edinson Volquez, but with Volquez struggling of late, having Hanigan behind the plate wasn't an attempt to shake up the battery for better results.
"It doesn't matter that much who is catching who, the pitcher has the ball in his hand," Baker said. "He still has to throw it to the glove. [Hanigan] usually catches Arroyo, and when Arroyo was struggling, no one asked about catching Ramon for Arroyo."