PITTSBURGH (AP) - Lyle Overbay's tiebreaking homer kept Miguel Batista unbeaten since moving into Arizona's starting rotation, and the Diamondbacks beat the Pittsburgh Pirates 2-1 Sunday.

Overbay drove in both Arizona runs as the Diamondbacks won for the second time in the three-game series and sent the Pirates to their eighth loss in nine games. The Pirates' 5-13 home record is the NL's worst.

Batista (3-2) made his sixth consecutive effective start, limiting the Pirates to one run and five hits in six innings. Since becoming a starter, Batista is 3-0 with three no-decisions while yielding only six earned runs in 38 innings, a 1.42 ERA.

Batista has allowed only two earned runs in his last three starts, limiting the Phillies to an unearned run in a complete-game 10-1 victory Monday.

Overbay's third homer, a drive that carried through a steady wind and over the right-field stands leading off the sixth, made the difference as Batista outpitched Pirates starter Kip Wells (1-2).

Wells, who has been Pittsburgh's most consistent starting pitcher despite winning only once in eight starts, was again hurt by wildness as he allowed two runs and five hits in seven innings.

The Diamondbacks hit only one ball out of the infield in the first inning, Overbay's two-out single into right field, but still took a 1-0 lead. Wells quickly got the first two batters, then walked Luis Gonzalez, one of 26 walks he has allowed in 51 1-3 innings. Matt Williams followed with a high-hop single that Wells couldn't corral behind the mound, and Overbay grounded a single past second baseman Abraham Nunez into right.

Arizona didn't threaten again until Overbay, who came out of a 4-for-31 slump with two hits, hit the sixth homer allowed by Wells. It was Overbay's first homer since April 14 against Colorado.

Pittsburgh's only run came when Nunez's RBI single in the second scored Rob Mackowiak, who was hit by a Batista pitch to start the inning.

Arizona's defense made several exceptional plays in support of Batista and the bullpen. Manager Bob Brenly used three relievers to get through the seventh and eighth innings before Matt Mantei pitched the ninth for his sixth save in seven opportunities.

Center fielder Quinton McCracken made a sliding, on-his-stomach catch of Matt Stairs' sinking liner with runners on first and third in the fourth. Tony Womack went deep into the hole at shortstop to throw out Jack Wilson to end the eighth, although replays appeared to show Wilson safe.

Wilson, who rarely argues, was ejected after protesting the call to umpire Fieldin Culbreth. Manager Lloyd McClendon also came out to argue but, unlike Friday night's game, was not ejected. Notes: Arizona is 13-6 in Pittsburgh and 28-12 against the Pirates. ... Arizona starting pitcher Byung-Hyun Kim (bruised right ankle) will make a rehabilitation start Monday for Triple-A Tucson. ... The Pirates have lost seven of eight home games. They are 2-7 overall against NL West teams.

(Copyright 2003 by The Associated Press. All Rights Reserved.)

AP-NY-05-11-03 1625EDT