Published: May 20, 2009 01:15 am      

Four straight

LaRoches lead Bucs to 8-5 win

WASHINGTON — Adam LaRoche had a two-run double in the 10th inning Tuesday night, and the Pittsburgh Pirates won their season-high fourth straight, an 8-5 victory over the Washington Nationals, who lost their sixth in a row.

Both streaks feature plenty of offense.

The Pirates are averaging 9.5 runs in their last four games, including 11 against Colorado on Sunday and 12 against the Nationals on Monday.

Washington became the fourth team in major league history to score at least five runs in a six-game losing streak, according to STATS, LLC.

The Nationals rallied to tie the game with a run in the ninth, but another letdown from a bullpen with a collective 1-14 record allowed them to join the 1929 Pirates, 2004 Cincinnati Reds and 2005 Texas Rangers with such a streak.

Tom Gorzelanny (1-0), making only his fifth relief appearance in 156 games in the majors and minors, pitched 1 1-3 innings for the victory. Gorzelanny was recalled from Triple-A Indianapolis on Sunday.

Joe Biemel (0-3) took the loss for the Nationals, who had a rare decent effort from the bullpen until he took the mound in the 10th, his second inning of work. The Pirates went 20 straight batters without a hit until Ramon Vasquez singled to open the 10th.

Starter Jeff Karstens allowed four runs over six innings, and Andy LaRoche homered for the Pirates, who took a 5-0 lead.

Washington center fielder Willie Harris whiffed trying to field a ball on one hop, turning Brandon Moss’ weak flare into a two-run double in Pittsburgh’s three-run first. Washington starter Shairon Martis threw two wild pitches in the first three innings.

The Nationals rallied with Adam Dunn’s homer in the fourth and three runs in the sixth. Nick Johnson tied the game when he scored on a wild pitch after hitting a triple off reliever Sean Burnett with one out in the ninth.

Notes: Nationals 3B Ryan Zimmerman reached safely for the 37th consecutive game, keeping his streak alive with a bunt single in the sixth. ... Nationals CF Elijah Dukes (hamstring) remains sidelined. ... Ross Detwiler (5 innings, 3 runs) did enough in his first major league start Monday night that the Nationals will start him again Saturday against Baltimore. ... Nationals leadoff hitter Cristian Guzman, who had 122 plate appearances before drawing his first walk Monday night, got another one Tuesday.