BALTIMORE (AP) -- About four hours before the Orioles faced the Pittsburgh Pirates , manager Buck Showalter walked up to struggling Jake Arrieta and told the right-hander he would be replacing Brian Matusz as Baltimore's starting pitcher.
The element of surprise might have been a factor in Arrieta's exceptional performance. Unfortunately for Showalter, it's not a ploy that can be repeated.
Arrieta struck out nine over seven steady innings, Wilson Betemit had a season-high three hits and drove in three runs, and the Orioles cruised past the Pirates 7-1 Wednesday night for their fourth straight victory.
Demoted to the bullpen after an ineffective outing Friday night against Philadelphia, Arrieta turned out to be the logical replacement for Matusz, who fouled a baseball off his nose Tuesday during bunting practice and was at less than 100 percent.
The injury was only a bruise, but Showalter thought it was better to pitch Arrieta on four days' rest and use Matusz on Friday.
Arrieta (3-8) was dominant in ending a six-game losing streak. He gave up one run and seven hits, and the nine strikeouts matched a career high. It was the first win since May 2 for Baltimore's opening day starter.
"I'm not going to overthink it," Showalter said. "I tapped him on the shoulder about 2:30 in the food room and said, `You're pitching tonight.' It's kind of out of the bag. I can't do it in five days now, so that's a one-time pop."
Arrieta didn't have time to think about the pressure of trying to get back on track. And that was a good thing.
"I went back to doing some things I was doing when I was successful," he said. "Kind of made some things a lot more simple than they were a couple weeks ago. I wasn't thinking as much. Going out there and really executing. I think it was nice to be out there in the bullpen for a few games and just stop thinking about some things."
Now he's back in the rotation, and Showalter can only hope for a repeat performance Monday against the Mets.
"He had a good outing tonight and I'm proud of him," the manager said. "And he served a need we had with Brian, being cautious with him. His next turn in the rotation if he took it would be on (Monday). I don't see why anything he did tonight wouldn't dictate that he wouldn't do that."
Chris Davis hit a broken-bat homer and had three RBIs for the Orioles, whose four-game home winning streak is a season high. By taking two straight from the Pirates, Baltimore clinched its third successive series win.
Betemit, who went 3 for 3 and gave the Orioles a 5-0 lead in the sixth inning against Kevin Correia (2-6) with his eighth homer of the year.
Pittsburgh, which won five consecutive series before coming to Baltimore, has lost two straight games for the first time since May 22-23.
"No. 1, we need to execute better off the mound. No. 2, when we got chances to score runs, we have to perform the offensive fundamentals to go along with that," Pirates manager Clint Hurdle said. "The game is pretty simple when you break it down, and they have outplayed us back-to-back nights. It shouldn't be any surprise to anyone here that we're down two."
Pittsburgh got its lone run in the seventh on a bases-loaded groundout by Neil Walker , who struck out his first three at-bats.
The Orioles made it 7-1 in the bottom half when J.J. Hardy got his third hit and Davis followed with his 12th home run, the second in two games. The top part of his bat flew into the Baltimore dugout as the baseball took a path over the right field wall.
Baltimore finished with 13 hits, which made it easy to overlook the 0-for-5 performance by Brian Roberts . The Orioles' leadoff hitter went 3 for 4 Tuesday in his return from a 13-month layoff with a concussion.
Baltimore got a first-inning run when Hardy singled and came home on a double by Davis.
After Pittsburgh wasted a leadoff double in the second, the Orioles went up 3-0 in the bottom half. Mark Reynolds led off with a single before Betemit hit an RBI double and scored on a single by Steve Pearce .
The Orioles added an unearned run in the fourth following an error by Pirates left fielder Alex Presley .
NOTES: Orioles OF Endy Chavez , who strained his right hamstring Tuesday night, did not play and could be placed on DL before Baltimore begins a weekend series in Atlanta. ... Pittsburgh has lost two in a row after winning four straight and six of seven. ... Former Oriole LHP Erik Bedard will start for Pittsburgh in the series finale. Tommy Hunter will start for Baltimore. ... Hardy is 5 for 9 over two games following a 1-for-15 skid.