BALTIMORE -- Maybe it really is all about the 26th man.

The Orioles, a team that entered Tuesday's three-game set on the heels of a 1-6 road trip, deep in the cellar -- not just of the American League but in the entire Majors -- are now getting solid starting pitching, timely hitting and stingy defense. They are starting to believe they can win. And it all starts with No. 26, the uniform -- honoring the late Johnny Oates -- that was fittingly handpicked by new manager Buck Showalter.

The Orioles completed a three-game sweep of the Angels with a 5-4 walk-off win on Thursday night -- courtesy of Cesar Izturis' RBI single -- to continue to add credibility to "the Showalter Effect," an idea popularized by just about everyone but the man himself.

"That's really not for me to say," Showalter said when asked if his perfect 3-0 record signified a new start for the O's.

"I just step back and watch them over at first base knowing how challenging and painful this season has been so far. So, to see them have three days to feel good about themselves makes me feel good for them."

Buoyed by rookie starter Jake Arrieta's career-high 7 2/3 innings of two-run ball and Nick Markakis' defensive prowess and 2-for-4, two-RBI night, the Orioles completed their first three-game series sweep over the Angels since Sept. 17-19, 1999, giving a crowd of 17,362 at Camden Yards plenty of reason to get up on its feet.

"[Showalter] brings a lot to the team," said Arrieta, who had a no-hitter going until two outs into the fifth. "Everybody has a lot of respect for Buck and we just want to play our best behind him and show that we are capable of winning games and beating good teams."

"There's a different feeling in the clubhouse," said Markakis, who broke a scoreless tie with a solo homer in the sixth. "I don't know what exactly it is, but it's a good one right now."

You can excuse the Orioles if they aren't quite sure what to make of what has transpired in Baltimore the last three days. The O's have hit .455 (15-for-33) with runners in scoring position, after recording just 13 hits in those scenarios in their previous 13 games. They've gotten three straight quality starts for the first time since May 17-19 and are gunning for what would be a season-high four straight with Friday's season opener. They are taking extra bases, laying down the bunt when they aren't asked -- such as Corey Patterson's sacrifice in the ninth -- and perhaps most importantly, they are learning how to come together and win.

"These guys got a second wind with Buck Showalter coming in," said Angels outfielder Torii Hunter, who belted a three-run game-tying homer in the eighth. "They had a little life. I've been watching these guys on TV, they're totally different these last three games.

"I think it's a little bit of spark they have over there right now."

And on Thursday, Arrieta provided the match. Making his 11th career start, Arrieta retired the first 14 batters, using a low fastball that topped out at 95 mph to keep the Angels' bats in fits. Alberto Callaspo's right-field double, just out of the reach of a diving Markakis, was the only hit through six innings as Arrieta, back from a trio of rocky starts, turned in arguably his best outing this season.

"That's the most strikes with the best stuff I've seen him have," catcher Matt Wieters said of Arrieta, who had 13 walks in his previous 13 2/3 innings, but issued just two free passes -- both in his final inning -- on Thursday.

"It's just a matter of making a few minor adjustments," Arrieta said of the career-high 108-pitch outing. "The stuff wasn't any better than it has been all year. It's just a matter of being more aggressive in the zone early and it makes a big difference throughout the course of the game."

Arrieta exited -- to a standing ovation -- with runners on the corners, two outs into the eighth inning, after a botched double play by Brian Roberts kept the frame alive. Reliever Michael Gonzalez allowed Bobby Abreu an RBI single and Showalter promptly inserted reliever Jason Berken, who gave up Hunter's game-tying homer. Still, Showalter stuck with Berken, who entered the game tops in the American League in innings pitched, and proceeded to toss a scoreless ninth.

"I'm glad Buck stuck with me," Berken said. "That means a lot. I was glad I was able to go out there, throw up a zero for us and give us a chance to come back next inning and get a win."

And that's exactly what they did.

Wieters stroked a double into left-center field off reliever Francisco Rodriguez to open the inning and Patterson's sacrifice moved Lugo, who was running for Wieters, over to third. With an odd defensive shift that featured Hunter in the infield, Izturis laced a pitch into center field to empty the home dugout in celebration.

It was a sight the Orioles could get used to.

"We have the talent, there was no doubt about that," Markakis said.

"As a team we know what we can do. It's just a matter of doing it and going out there and putting it together. And lately that's what we've been doing. We can hope on it, build on it, and go from there."