PITTSBURGH – Yoslan Herrera pitched six shutout innings for his first major league win, and the Pittsburgh Pirates got back-to-back homers from Jason Bay and Xavier Nady in a 9-1 victory over the San Diego Padres on Thursday night.

Nate McLouth also homered and had three RBIs for the Pirates, who have won four straight. They stopped a six-game skid against the Padres, who have lost nine of 10 overall.

San Diego owns the worst record in the major leagues at 38-65.

Herrera (1-1), making his third big league start since being called up from Double-A Altoona on July 12, allowed six singles and one walk while striking out four in his 96-pitch outing. The 27-year-old Cuban defector, who allowed 13 runs over six innings in his first two starts, lowered his ERA from 19.50 to 9.75.

Bay and Nady opened the fourth with home runs against Clay Hensley (1-1) to give Pittsburgh a 4-0 lead.

Bay’s homer was his 139th with the Pirates, moving him past Hall of Famer Bill Mazeroski for eighth place on the franchise list. Bay, who also had a first-inning sacrifice fly, has 15 RBIs in his past 10 games. Nady, who had two hits and scored twice, extended his hitting streak to 13 games.

McLouth, who had a sacrifice fly in the sixth, hit a two-run shot in the eighth against reliever Bryan Corey.

Hensley, making his first start of the season, allowed six runs and seven hits in five innings. He struck out two and walked two.

Adrian Gonzalez had two hits and an RBI for the Padres.

Notes: San Diego manager Bud Black said RHP Chris Young, on the disabled list since May 22 with a broken nose, is scheduled to throw a side session Saturday and could start Tuesday against Arizona. … The Padres, who faced the Pirates for the first time this season, are 7-0 in series at PNC Park. San Diego is 14-8 in Pittsburgh since the ballpark opened in 2001. … Pittsburgh’s Freddy Sanchez is hitting .424 (14-for-33) in eight games since the All-Star break. … The back-to-back home runs were the first for the Pirates this season. … The Pirates are 13-2 when Bay has two or more RBIs.

AP-ES-07-24-08 2157EDT