PITTSBURGH -- John Lannan continues to make a midseason demotion to Double-A pay dividends.
He allowed only one run for the second consecutive start, Ivan Rodriguez had three hits and four RBI and the Washington Nationals broke a three-game losing streak with a 9-2 win over the Pittsburgh Pirates on Saturday night.
Lannan improved to 5-1 with a 2.93 ERA in seven starts since returning from a six-week stint in Double-A to rehab his mechanics and confidence.
"Now he's the John Lannan everybody knows," Rodriguez said of Washington's Opening Day starter. "He's the guy who pounds the strike zone, keeps the ball down and moves the ball around. He's a good pitcher, and he's going to be fine."
Rodriguez homered for the 308th time in his career in the fifth, an inning after hitting a two-run single off the wall as part of a five-run Nationals' fourth. It was his first four-RBI game since having five June 15, 2007.
"That's why he's a Hall Of Famer," Lannan said. "He's going to have those days. The home run was huge -- it put us over the top -- and he was great behind the plate."
Pittsburgh rookie Neil Walker doubled to extend his hitting streak to 11 games, and Paul Maholm took over the National League lead in losses with his 14th.
Lannan came in a combined 0-10 in 15 career starts against teams from Pennsylvania, including 0-3 lifetime against the Pirates. He allowed only an Andrew McCutchen solo home run and four other hits and a walk in seven innings, striking out seven.
"Since the demotion and coming back up, I'm just trying to finish the season strong," Lannan said.
Lannan allowed one run on eight hits in 7 2/3 innings of a 4-2 win over St. Louis in his most recent outing Aug. 29.
"He's really on a streak now," said Nationals bench coach John McLaren, who managed the team while Jim Riggleman served the second game of a two-game suspension for a bench-clearing incident Wednesday against Florida. "He feels good about himself and has really done a good job for us here the last two months. He's been really, really good.
"It looked like before his mechanics were out of whack and he lost his confidence, and that's a bad combination. He came back, got his confidence back and he's on a roll now."
Although Washington did not have a hit through three innings, 10 of the next 13 batters would reach against Maholm -- and two of those retired were on sacrifices.
After the Nationals loaded the bases, Rodriguez singled off the wall in right to drive in two runs. Danny Espinosa followed with an RBI single and Justin Maxwell hit a sacrifice fly to deep left-center to make it 4-0.
After a Lannan sacrifice, Nyjer Morgan singled in Espinosa.
Michael Morse led off the following inning with a single and Rodriguez then hit his third homer.
That ended Maholm's night. He lost his fifth straight decision, allowing seven runs on eight hits and two walks with four strikeouts. Maholm (7-14) is 1-7 since shutting out the Houston Astros July 18.
"It's about as frustrating as you can get right now," Maholm said.
"I expect a lot out of myself, and other people expect a lot. I haven't pitched the way I'm supposed to, so I'll take this as a learning experience. It definitely can't get any worse."
Maholm has allowed 46 earned runs in 46 2/3 innings over his past nine starts.
"He wasn't commanding the ball the way he wants to," Pirates manager John Russell said. "It's something that's continuing to kind of get him."
McCutchen's home run, a line drive to left in the fifth, was his 13th of the season and first since hitting four in five days from Aug. 16-20.
Former National Lastings Milledge had three hits for the Pirates, who have the majors' worst record. They had won four of their previous five at PNC Park.
Washington SS Ian Desmond went 3-for-5.... Washington has not announced who its starter Tuesday against the Mets will be, but Riggleman did say it would not be LHP Scott Olsen and will be a player the club recalls from the minors. Olsen will be, at least temporarily, moved to the bullpen. ... The Pirates announced that 1B Jeff Clement, already on the disabled list, is out for the season with a pulled oblique muscle.