CINCINNATI -- Dave Williams knew he had a four-run lead, yet pitched as though the game was much tighter.
"Williams did a good job," Cincinnati manager Dave Miley said. "He looked like he was trying to pitch like it was 0-0."
Ty Wigginton hit a two-run shot in the second and Humberto Cota added a solo homer in the third to give him three RBI and boost Pittsburgh's lead to 7-0.
Williams walked the first two batters he faced, but settled down and didn't allow a hit until pinch-hitter Jacob Cruz doubled in Javier Valentin, who walked with two outs in the fifth.
Williams (5-4) matched his longest outing of the season and won for the fourth time in five starts. He walked five and struck out five.
"He was erratic in the first inning," said Cota, Pittsburgh's catcher. "He looked like he was pushing the ball. I went out and talked to him after he walked the first two guys, and I said, 'We might have four runs, but you still have to pitch."'
Waiting around while his offense built the big lead might have affected the Pirates' starter.
"I don't know if I was sitting too long or what," Williams said. "After the two walks, I had to regroup. I had to be aggressive. I didn't want to put runners on and have their big guys hit one out."
Pittsburgh jumped out to a 4-0 lead with its biggest first inning of the season. Freddy Sanchez doubled on Eric Milton's second pitch, and Bay followed one-out later with his 11th homer -- a 412-foot shot into the upper deck in left field. After Wigginton struck out, Jose Castillo singled and moved to third on Michael Restovich's ground-rule double to right-center. Both runners scored on Cota's bloop single to right.
The Pirates added two runs in the second on Sanchez's leadoff single and Wigginton's fifth homer of the season. He has hit them all in his last eight starts.
Sanchez was playing with nine stitches in his left wrist after getting cut by Felipe Lopez's broken bat while fielding a grounder on the last play of Friday's game.
Cota made it 7-0 by leading off the third with his third homer, his third RBI of the game.
"Cota's had a lot of big hits this season," Pittsburgh manager Lloyd McClendon said. "I really think he can be a run producer. I really think he can drive in runs."
Milton (3-6), who has given up a major league-leading 20 home runs this season, allowed nine hits and seven runs in three innings -- the shortest of his 11 starts this season. He was coming off his best start of the season -- six hits and one earned run in a season-high eight innings on Monday.
"That doesn't mean anything now," said a subdued Milton, who yielding an NL-leading 43 homers last season with Philadelphia. "It's back to square one."
"We were hoping to get the same type of outing," Miley said. "He just wasn't as sharp."
Lopez made it 7-2 in the eighth when he hit his third home run in four games and eighth of the season.
"We had a lot of hittable counts," Miley said. "We just didn't get hits."
Sanchez batted leadoff for the first time in his career. ... Wigginton batted cleanup and started at first base each for the first time this season. ... Lopez extended his hitting streak to 10 games, matching the career high he set last season. ... The Pirates improved to 15-8 at Great American Ball Park, the most wins by a visiting team. ... The Reds retired uniform No. 10 in honor of Hall of Fame manager Sparky Anderson. ... Cincinnati SS Rich Aurilia began a rehab assignment at Triple-A Louisville. Aurilia has been on the disabled list since May 11 with a strained left hamstring.