Britton retired nine of 10 batters before Casper Wells tripled to lead off the sixth and scored on Mike Carp's single. Left fielder Nate McLouth initially was charged with an error after falling and letting the ball roll past him, but Wells is now credited with a three-bagger.
Kevin Gregg replaced Britton, and Carp eventually scored after Wilson Betemit committed the Orioles' second error of the night and Dustin Ackley lined an RBI single to center field. Miguel Olivo, who reached on the error, was cut down at the plate on a nice throw from center fielder Adam Jones.
Britton is charged with four earned runs (seven total) and eight hits in five-plus innings, with two walks, six strikeouts and two home runs. He threw 87 pitches, 48 for strikes.
Britton's ERA is 8.10. It actually has gone down from 8.35.
Betemit has committed 13 errors at third base, one at first and one in left field.
Matt Wieters homered again in the sixth, the third two-homer game of his career and the second this season. It also happened on April 16 in Chicago.
Mariners 7, Orioles 3.
Both home runs tonight have been to straightaway center field.
Meanwhile, Arrieta lasted only 3 2/3 innings with Triple-A Norfolk. He's charged with five runs and eight hits, with three walks, no strikeouts and a hit batter. He threw 80 pitches, 48 for strikes.
Former Oriole Felix Pie, now playing for Triple-A Gwinnett in the Braves' system, had an RBI double and two-run single off Arrieta.
Tonight's attendance: 15,433
Update: It's a whole new ballgame.
The Orioles scored four runs in the seventh inning, the last three on J.J. Hardy's 16th home run of the season.
Orioles 7, Mariners 7.
Mark Reynolds led off with a double - he's reached base two more times tonight - and Omar Quintanilla followed with an RBI single off reliever Lucas Luetge on a ball that second baseman Dustin Ackley knocked down but couldn't control. Nick Markakis singled, making him 3-for-4, and Hardy followed with a bomb to left field.
Britton is off the hook.
Wieters doubled off reliever Stephen Pryor with two outs. He's also thrown out a runner trying to steal and tagged out a runner at the plate. He's having a pretty good night.
Update II: In case you just tuned in, the Orioles became the first team this season to play into the 13th inning five times. They won the first four.
The bullpen has turned in eight scoreless innings tonight. Robert Andino guaranteed that the Mariners didn't break the 7-7 tie in the top of the 13th by making a diving stop and throw to retire Kyle Seager with Eric Thames on second base.
Jim Johnson is the only reliever left in the Orioles' bullpen.
Update III: Make it 12 extra-inning wins in a row, and 11 straight one-run victories.
Omar Quintanilla led off the bottom of the 14th with a disputed infield hit - first base umpire Brian Knight ruled that second baseman Dustin Ackley's throw pulled Mike Carp off the bag - and Nick Markakis followed with his fourth hit. J.J. Hardy laid down a sacrifice bunt and reliever Shawn Kelley walked Chris Davis intentionally to load the bases for Adam Jones.
Jones sent everyone home with single into right field, the ball getting past a sliding Casper Wells.
Tommy Hunter, who's supposed to start tomorrow night, was warming in the bullpen and would have pitched the 15th, which probably would have led to Steve Johnson being recalled from Triple-A Norfolk, since he's also scheduled to start tomorrow night.
We'll find out later if the Orioles need to make a roster move.