A night after overcoming a three-run deficit to beat the Florida Marlins, the Orioles dug themselves out of a six-run hole against the Washington Nationals and then got a little help to score the winning run.

Second baseman Cristian Guzman's throwing error in the ninth inning on Julio Lugo's potential inning-ending double-play ball allowed Jake Fox to score from second and the Orioles to celebrate a 7-6 victory last night at Camden Yards.

First baseman Adam Dunn couldn't dig out Guzman's low throw and the ball bounced into foul territory. The Nationals' fourth error of the game, leading to four earned runs, completed the Orioles' biggest comeback this season. The Orioles, who have won back-to-back games for the first time since May 13 and 14, trailed 6-0 after four innings.

"It wasn't looking good for us early on," said Orioles outfielder Corey Patterson who tied the game in the eighth inning with an RBI single. "I think there was a lot of heroes in this game. Pick one. In my mind we just played great as a team, and that's the way we have to do. It was definitely exciting."

Most of the 43,484 in attendance stayed through the three hour, 53 minutes game, which featured 10 total pitching changes. But what appeared to be another lopsided Orioles' loss morphed into a thrilling finish.

Trailing by three heading into the bottom of the eighth inning, the Orioles (21-52) got a two-run homer by pinch-hitter Scott Moore, who drove Tyler Clippard's 3-1 fastball onto the flagcourt in right field. Moore had been 1-for-17 with 10 strikeouts in pitch-hit opportunities over his career. Cesar Izturis then hit a one-out double before he scored on Patterson's single to tie the game

"When we tied the game in the eighth inning, it was huge," said Moore. "We all felt like we were going to win the game."

The Orioles had to sweat through a tenuous top of the ninth as Orioles closer Alfredo Simon got Roger Bernadina to ground out on a close play at first with runners on the corners and two outs.

In the bottom of the ninth, Matt Wieters worked a leadoff walk and then Scott dumped a single into center field off Clippard. Nationals closer Matt Capps came in and got exactly what he wanted in a seemingly routine double play ball off the bat of Wieters. Shortstop Ian Desmond, whose two errors contributed to a three-run fifth inning and started the Orioles' comeback, fielded it cleanly and flipped to Guzman for the first out.

However, Guzman's throw was both low and off line and Dunn's stretch for it came up short. Fox, who was pinch-running for Wieters, crossed home plate without a throw and was mobbed by his teammates.

"I have to tip my hat to this team, after falling behind," said interim manager Juan Samuel. "These guys didn't quit. We kept plugging and plugging."

Twice, the Orioles thought that they had the hit that would get them back in last night's game, only to watch Nationals center fielder Nyjer Morgan take them both away with his blinding speed and sheer athleticism.

Morgan elevated well over the center-field wall to take away a Patterson solo homer in the third inning, a breathtaking catch that was so good that Patterson raised him helmet in salute of the Nationals center fielder.

"That's one of the finest [catches] I have seen," said Samuel.

Then in the fifth, Morgan sprinted to deep left center field to snatch Miguel Tejada's drive with the bases loaded and no outs. Orioles starter Jake Arrieta could have used the help that his counterpart J.D. Martin got, but the reality was that the rookie didn't give his teammates much of a chance.

In his fourth big-league start, Arrieta was pounded for six runs (five earned) on eight hits and three walks over just 4 1/3 innings as he left the game with the Orioles trailing 6-0. After winning his first two starts, Arrieta has allowed 10 earned runs, 13 hits and six walks over 7 1/3 innings over his last two, but was bailed out of a potential loss last night by the Orioles' offense.

"You got to give credit to our offense, the way they swung the bats," said Arrieta. "I don't know if I saw more than one or two at-bats that weren't quality. … It's great for our club right now. That's something we really needed and it gives us a lot of momentum going forward."

Arrieta had several problems last night, most related to spotty command. He also couldn't prevent Morgan, the Nationals leadoff man, from getting on base and Adam Dunn, the cleanup hitter, from driving him in.

In addition to his two fabulous defensive plays, which certainly made up for his gaffe in the last series between the two teams when his display of frustration allowed Adam Jones to get an inside-the-park home run, Morgan went 4-for-5 with three runs scored and an RBI. Dunn drove in four runs and it was his two-run double in the fourth that gave the Nationals a 6-0 lead.

But the Orioles' bullpen turned in 4 2/3 innings and the offense did the rest.

jeff.zrebiec@baltsun.com