CINCINNATI -- Ken Griffey Jr. did his part in giving starter Brandon Claussen a healthy lead to work with.
The Reds also scored one in the first and two in the third to build a 9-0 advantage.
"Any time you can make your starting pitcher comfortable, it's important," said Griffey, who drove in season-high five runs. "Being up seven after two innings helps him out."
LaRue went 3-for-4 with three RBI and three runs scored as the Reds matched their largest winning margin of the season and completed a 6-4 homestand. The Pirates have lost six of eight after splitting the four-game series.
"It's nice to come out and pound a team early," Claussen said. "It takes a load off. You can just throw the ball and let them hit it."
Claussen (2-3) went a career-high 7 2/3 innings to earn his first win in five starts. The left-hander allowed seven hits and two runs.
"He had outstanding command of all of his pitches," said manager Dave Miley, who heard boos when he went to the mound to remove Claussen.
Those quickly changed to a standing ovation for the starter.
"That was well-deserved," Miley said. "He did a tremendous job."
Pittsburgh starter Kip Wells (3-4) lost for the first time in eight starts. Wells, victimized by four walks and two infield errors that led to five unearned runs, allowed six hits and a career-high nine runs in 2 2/3 innings, his shortest non-injury outing since he lasted 1 1/3 innings against the Reds on April 10, 2002.
"It wasn't a good day," Wells said. "If I'm going to have a bad day, I might as well make it one that encompasses all avenues. Just scratch it and move on. I'm not going to overanalyze it. They did a good job of taking advantage of having me on the ropes, and they didn't let me off the hook."
The Reds, who trailed 4-0 after the first inning Saturday, converted shortstop Jack Wilson's throwing error into a first-inning run on Griffey's sacrifice fly.
"Kip really didn't have his stuff or his command," Pittsburgh manager Lloyd McClendon said. "We've been getting good starts lately, and this is a bump in the road."
LaRue started the second-inning scoring with his third homer, a two-run shot to center field. LaRue, who missed the previous four games after getting hit by a pitch on his left wrist on Tuesday, extended his hitting streak to eight games (13-for-32, .406).
Wells then walked Claussen and Ryan Freel, who was erased at second on Felipe Lopez's fielder's-choice grounder. Third baseman Freddy Sanchez's throwing error on Casey's routine grounder allowed Claussen to score and set up Griffey's three-run homer -- his seventh and first in 32 at-bats.
"The errors just compounded things," McClendon said. "It was just not a good day all around."
The Reds added two runs in the third on doubles by LaRue and Freel, who also had three hits to snap a 1-for-14 slump. Cincinnati scored single runs in the sixth and seventh.
Freel also robbed Ty Wigginton of an eighth-inning homer with a leaping catch at the center field fence.
The Pirates broke up the shutout on Wigginton's leadoff double and Humberto Cota's two-out single in the fourth. Michael Restovich added his second homer in the sixth.
Reds INF Rich Aurilia made his first start of the season at third base after being activated from the 15-day disabled list Sunday. ... 1B Sean Casey returned to the lineup after not starting four straight games because of a bruised left rotator cuff. He extended his hitting streak to six games (9-for-17, .529) with a fourth-inning infield single. ... OF Jason Bay has started each of Pittsburgh's 48 games. ... Griffey needs three home runs to reach 511 and tie Mel Ott for 18th place on the career homer list. He needs four to tie Ernie Banks and Eddie Matthews for 16th. ... Lopez extended his hitting streak to a career-high 11 (15-for-46, .326) with a sixth-inning double.