The San Francisco Giants' playoff hopes were dealt a big blow at the beginning of a challenging slate before they gave themselves a boost with another successful homestand.
The Giants have also hurt the Washington Nationals' chances in their latest series, and Madison Bumgarner will try to complete a four-game sweep Sunday while earning a share of the MLB wins lead.
San Francisco (63-53) is in the midst of a 26-game stretch against teams in playoff position or in second place in their respective divisions. The Giants started in miserable style with a four-game sweep in Chicago from Aug. 6-9, letting the Cubs zoom past them for the NL's second wild-card spot.
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They've won four of five - against Houston and Washington (58-58) - since their return home, and their hitters have led the way lately. San Francisco's 12-6 win Saturday gave it a combined 20 runs and 26 hits in the past two games.
Matt Duffy drove in four runs, giving him eight RBIs in the series, and Gregor Blanco had three hits for the second straight game.
The Giants, who have won 12 of 14 at AT&T Park, are within 2 1/2 games of the Los Angeles Dodgers in the NL West, but they're now 4 1/2 back of the Cubs in the wild-card race after Chicago extended its win streak to nine Saturday.
Washington is 9 1/2 behind the Cubs and 4 1/2 back of the New York Mets in the NL East after losing 12 of 16. The Nationals have also dropped eight of nine on the road.
Bumgarner (13-6, 3.15 ERA) will try to deliver the Giants' first four-game home sweep of the Nationals/Expos franchise since May 28-30, 1971. San Francisco swept a four-game road series and a three-game home set against Washington in 2008.
Bumgarner allowed six runs in five innings of a 9-3 loss at Washington on July 4 and has lost three consecutive starts against the Nationals, including Game 3 of the division series in San Francisco on Oct. 6.
The left-hander, though, is 5-1 with a 2.63 ERA in his six starts since last facing Washington. He tossed a five-hitter in a 3-1 victory against Houston on Tuesday while striking out 12 and walking none.
Bumgarner, who has logged a 1.84 ERA while winning his last four home starts, also fanned seven straight batters to tie the most in a row by a Giants pitcher since the club moved to San Francisco.
"Just being able to watch him day in and day out, it's pretty special to see a talent like him. He's the guy that we all feel like when he's out there, we're going to win the ballgame," first baseman Brandon Belt told MLB's official website.
Nationals rookie right-hander Joe Ross (3-4, 3.44) will make his first start in his native Bay Area and try to bounce back from his worst outing. He gave up five runs in 4 2-3 innings in his eighth major league outing, a 5-0 loss to the Dodgers on Tuesday.
"He's pitched in some big games for us," manager Matt Williams said. "He'll be ready for it."
Bryce Harper hit a two-run homer off Bumgarner in the first inning in July and is 4 for 11 with two homers versus him. The Nationals slugger, who has an NL-best 30 homers, fouled a ball off his left foot Saturday but said X-rays were negative.
Anthony Rendon is 5 for 9 against Bumgarner, including playoffs, but has gone 0 for 10 in this series.
The Nationals haven't been below .500 since they were 14-15 on May 7.