Chris Dickerson, who is competing for playing time in both left and center, singled and stole two bases. He scored the Reds' first run of the game on the first of Joey Votto's two RBI ground outs. Dickerson is hitting .371 this spring and was on base twice.
Homer Bailey pitched five solid innings, allowing just one run. Bailey will break camp in the starting rotation after starting each of the last three seasons in the minor leagues.
"You shouldn't have a different mindset even though you do. As long as you get the work in, everything should take care of itself," Bailey said. "I guess I have a little bit more leeway."
Manager Dusty Baker said Bailey was "full of determination" during the outing.
"He wasn't quite as sharp today. He was around the plate," he said. "He had good velocity and made pitches when he had to."
The Giants' Jonathan Sanchez had allowed nine earned runs in 11 innings over his first four starts this spring. The Reds scored three but only two were earned on four hits and two walks.
San Francisco manager Bruce Bochy said Sanchez' had an improved outing.
"I was looking for a fastball the at-bat before but I missed it," Renteria said. "I am not a home run hitter. I am working on seeing the ball. I have been driving the ball though."
Cincinnati closer Francisco Cordero allowed a run for the first time in his seventh spring appearance.
The run scored on a throwing error by third baseman, Aaron Miles. Miles, who broke the middle finger on his throwing hand early in training, threw wild to first to allow Mark DeRosa to score. Miles was acquired in a trade for Adam Rosales to give veteran strength to the Reds' bench.
"DeRosa has been fine," Bochy said. "We aren't familiar with this park. It's kind of tricky."
Veteran Arthur Rhodes has allowed just two hits and a walk in five official appearances. He allowed three runs on five hits in a "B" game on March 14.
The Giants have scored in the first inning in each of their last six games. ... Aroldis Chapman took treatment on his lower back Wednesday morning and had a meeting with Baker, who told him to communicate his injuries. "In Cuba guys are taught not to complain," Baker said. Chapman left after the meeting to get a social security card, then returned for treatment. ... Edinson Volquez threw 45 pitches off a mound Wednesday morning. Volquez is recovering from surgery to his right elbow.