The bloop hit scored Franklin Gutierrez from third base. He opened the final inning with a single off Athletics left-hander Dana Eveland, who started Friday night's series opener. Eveland contributed a throwing error to second base after fielding a bunt, and after walking Ichiro Suzuki intentionally to load the bases, Lopez came to the plate with a chance to deliver his second walk-off hit of the series.
He swung hard and center fielder Rajai Davis reacted. He took two steps back, realized he had gone the wrong direction but had no chance to correct his mistake and reach the ball, and for the third time in the three-game series, one run separated the two teams.
It also was the longest Major League game of the season, in innings and time. The 526-pitch marathon lasted 5 hours, 3 minutes.
One reliever, Athletics left-hander Gio Gonzalez, threw more pitches (108) than Oakland's starter, and Mariners reliever Miguel Batista threw 65 pitches from the 11th through 13th innings, just 13 fewer than starter Chris Jakubauskas.
"It was a wonderful game," veteran Mike Sweeney said. "It was tough falling behind the way we did, but there was a rumbling in the dugout, and a feeling, that we are not going to give up. Even when were down by three runs in extra innings, we never quit. We showed a lot of character."
Sweeney contributed mightily to the first comeback, slugging a two-run home run off Athletics starter Josh Outman in the fourth inning. It was his first home run of the season, and the 200th of his career.
The 35-year-old Sweeney, who signed a Minor League contract with the Mariners in January, hit his first 197 MLB home runs during an illustrious career with the Royals from 1995-2007, and added two more with the Athletics last season.
"By no means is it a milestone like Junior [Ken Griffey Jr.], who has 600-something, but it's a small milestone for a big league player," he said. "For a guy like me, a late-round Draft pick who takes pride in my work ethic, it's quite an honor, especially considering that when I was released by the A's, I didn't know if I would ever get a chance to play in the big leagues again.
"Being stuck on 199 for the rest of my life wouldn't have been fun. But to get it in a game where it means something, and being against Oakland, helps a little bit, although by no means is there any ill-will."
As he crossed home plate, Sweeney smiled and pointed into the Mariners dugout at bench coach Ty Van Burkleo.
"Ty practiced his calligraphy during the winter and he writes an impeccable lineup card," Sweeney related. "He said in my last four or five starts he had made extra lineup card so I could have one to hang on my wall."
Sweeney's home run was a personal milestone, but the Mariners were still training by two runs going into the seventh inning. Ichiro Suzuki delivered a run-scoring single in the seventh to chop a two-run deficit in half and catcher Kenji Johjima tied the game in the ninth with a one-out solo home run to left field.
That took care of the first three-run deficit.
The one in the 13th inning had to be much quicker -- and it was.
Batista, the seventh of eight pitchers used by manager Don Wakamatsu, walked Davis to start the inning. Davis stole second and advanced to third when Johjima's throw went between Lopez's legs and into center field.
After Batista struck out Kurt Suzuki, he hit Bobby Crosby with a pitch and then struck out Gregorio Petit to ease the pressure. But the escape hatch closed when Landon Powell delivered a two-run double to right field on a full-count pitch, scoring two runs, and Orlando Cabrera added another run with a single into right field.
Sweeney said the mood in the home dugout was upbeat.
"We were saying, 'OK boys, this is our game to win. We haven't been playing this long to have the game slip away. We had to keep fighting and have good at-bats, and we did that."
Third baseman Adrian Beltre lit the fuse with a leadoff single up the middle. One out later, Wladimir Balentien singled into center field and Johjima walked to load the bases. Gutierrez walked to force in a run, Yuniesky Betancourt drove in a run with a forceout at second and Ichiro completed the comeback with a sharp single into center field.
"That was a phenomenal game to win," Wakamatsu said. "It shows the character of this club. I mean, to be down three runs like that and be willing to take some walks, was very impressive. This was a game of attrition and although Batista gave up three runs, he ended up throwing 65 pitches and allowed us to go to [Jason] Vargas later.
"But the thing that stands out for me is these guys just don't give up," he added. "It would have been easy to pack it in."
Vargas, promoted from Triple-A Tacoma on Friday, pitched the final 2 1/3 innings and picked up the win in his first relief appearance in the Majors since July 3, 2007. It was his first big league win since April 3, 2006.
He also was the last line of defense for Seattle.
"I knew I was the last one out there and could have thrown 100 pitches if I had to," he said.
The Mariners climbed within a run in the seventh inning when a single, walk and RBI single by Ichiro closed the gap and put runners on first and third bases. But Lopez flied out to deep right-center to end the inning.
Jakubauskas made his third start since replacing the injured Ryan Rowland-Smith and surrendered his first big league home run -- a two-run opposite-field blast into the visiting bullpen by Jack Cust, capping a three-run first inning rally by the visitors.
Ground-ball singles to the first two batters he faced in the series finale, along with two infield outs, produced the first run of the game.