By NICOLINO DIBENEDETTO
(AP) -- Superb pitching from their rotation is a big reason the Washington Nationals are tied for the most wins in the majors.
The well-traveled Edwin Jackson is among those impressive starters.
Jackson looks to build on a brilliant performance by helping the Nationals complete a sweep of this four-game series with the Houston Astros on Thursday night.
Washington (10-3) is tied with Texas for the most wins in baseball, and that's thanks in large part to a major league-low 1.65 ERA from a rotation consisting of Jackson (1-0, 2.57 ERA), Stephen Strasburg, Gio Gonzalez, Jordan Zimmermann and Ross Detwiler.
"No one wants to be the weakest link. And when you have a staff like that, to where it's competitive but it's fun, it's always great," Jackson said.
Jackson, a veteran of seven teams in nine-plus seasons, didn't look like a weak link Saturday, striking out nine in a 92-pitch two-hitter in a 4-1 victory over Cincinnati.
The right-hander is 2-0 with a 3.65 ERA in five games - four starts - against Houston.
The Nationals got another impressive performance on the mound in Wednesday's 3-2 win over Houston (4-8). Zimmermann and two relievers combined on a six-hitter before Jayson Werth drew a bases-loaded walk, and Wilson Ramos connected for a sacrifice fly for the go-ahead run in the eighth.
"A win's a win, no matter how we get it," Zimmermann said. "We're getting in the late innings the last couple games, which makes it extra exciting."
While pitching has been key for the Nationals, Ryan Zimmerman has collected five hits and two RBIs in this series. Producing against the Astros at home isn't anything new for the third baseman, who's hitting .406 with five doubles, three homers and 14 RBIs in his last 16 matchups in the nation's capital.
Zimmerman is 3 for 7 with a homer off Bud Norris, Thursday's scheduled starter.
The Nationals have won 10 of 12 at home against Houston, and Norris (0-0, 3.46 ERA) isn't surprised by Washington's overall success in 2012.
"They're a good ballclub," Norris told the team's official website. "They've got pitching and a lot of things going their way."
Things certainly haven't been going the Astros way, as they've dropped seven of eight, and are trying to avoid their first five-game slide since losing seven straight from Aug. 9-15.
Norris gets the ball seeking his first win since beating the Chicago Cubs on Aug. 17. The right-hander is 0-3 with a 4.21 ERA in eight starts since, but his two appearances this season have resulted in Houston victories.
Norris allowed four runs - three earned - and six hits in six innings before the Astros scored four runs in the ninth for a 5-4 win at Miami on Saturday.
He's 1-0 with a 2.63 ERA in two starts against the Nationals with both coming in Washington.
Chris Johnson is 0 for 7 after his hitting streak reached nine games with a three-hit effort that included a triple and three RBIs in Monday's 6-3 series-opening loss.
Updated April 19, 2012