The Pittsburgh Pirates' recent surge combined with their staggering success at home has made them the surprise leaders in the NL Central.
The San Francisco Giants' struggles have cost them their division lead.
The Pirates will try to capitalize on the slumping Giants and continue their dominance at PNC Park in the opener of this three-game series Friday night.
Pittsburgh (46-36) has won eight of nine, erasing a three-game deficit in the division to overtake Cincinnati for first place heading into the final series before the All-Star break.
"It means we're not going to sneak up on anybody anymore," manager Clint Hurdle said. "We're confident, not cocky. We've worked hard to get to this spot. We're making our way."
That's certainly true at home, where the Pirates' 27-13 record is the best in baseball. They've won 16 of 19 at PNC after beating Houston 2-0 on Thursday to complete a four-game sweep.
Despite being held to five hits in the finale, Pittsburgh is batting .325 with 16 homers and averaging 7.6 runs during its 8-1 run.
Andrew McCutchen is hitting .525 with four homers and 14 RBIs in his last 11 home games. But the center fielder, who will join closer Joel Hanrahan at Tuesday's All-Star game, is a lifetime .205 hitter against San Francisco (45-38) - his worst average versus any NL opponent.
The Pirates will give the ball to Erik Bedard (4-9, 4.57 ERA), who's 0-3 with a 7.65 ERA in his last four starts. The lone quality outing in that bunch came at home, where the left-hander is 2-0 with a 1.42 ERA in his past three starts.
His troubles on the road continued Sunday, when he surrendered five runs and eight hits - two homers - in 4 2-3 innings of a 5-4 loss at St. Louis.
Bedard's lone start against the Giants came with Baltimore on June 12, 2004.
San Francisco has relinquished its lead in the NL West to Los Angeles after losing five of six. The Giants were on the verge of salvaging their finale at Washington on Thursday, but closer Santiago Casilla gave up two runs in the ninth of a 6-5 loss.
They'll now call on Barry Zito (6-6, 3.84), who has lost three of four road starts with an 8.84 ERA. The left-hander has dropped the last two as the visitor while getting hammered for 16 runs and 14 hits with seven walks in 6 1-3 innings.
Zito battled through his latest outing at home Saturday, walking six but holding Cincinnati to one run and five hits in six innings of a 2-1 loss.
"It was a good effort," manager Bruce Bochy told the team's official website. "He got off a couple innings there and battled himself. He threw six innings and gave up one run; that's a great job."
Zito is 1-3 with a 3.25 ERA in six starts against the Pirates, including a pair of losses in Pittsburgh. He was solid in the most recent meeting at home April 14, yielding three runs in seven innings.
McCutchen is 5 for 13 against Zito and leads the majors with a .446 average against left-handers.
The Pirates last won five straight Sept. 17-22, 2010, failing to extend their past six four-game streaks.