One constant through this 18-inning marathon was the sight of Mariners catcher Miguel Olivo guiding a staff of pitchers through their paces.

He'd helped starter Erasmo Ramirez deliver eight initial scoreless innings, then nursed another seven relievers through the game after the Baltimore Orioles tied it with a pair in the ninth. Olivo even supplied all of his team's offense with an early home run, but it wasn't enough to avoid a 4-2 defeat early Wednesday morning in one of the longest games in Mariners history.

"I'm a little tired, I'll be honest with you," a sweaty Olivo said after the five-hour, 44-minute contest was done. "This game got me a little bit."

Fewer than a thousand fans from the initial 12,608 at Safeco Field appeared to still be at the park by the time Baltimore reliever Jim Johnson closed things out in a 1-2-3 bottom of the 18th. The Orioles had scored twice in the top of the inning off Mariners reliever Lucas Luetge, with a go-ahead single blooped to right by Taylor Teagarten giving Baltimore its first lead in nearly two games of action.

The 18 innings tied for the fourth-longest game in Mariners history, while the time it took was the fifth longest in any Seattle contest.

Luetge was into his second inning of work after Sean Kelley, Oliver Perez, Stephen Pryor, Josh Kinney and Tom Wilhelmsen had kept the Orioles off the scoreboard in extras. The Mariners went 0 for 17 with runners in scoring position, squandering a leadoff double by Kyle Seager in the 17th and a leadoff walk by Olivo — his career-high third of the night — one inning prior.

For the Orioles, their franchise-record 14th consecutive extra-innings win demonstrated how they've managed to stay neck-and-neck with the New York Yankees for first place in the American League East despite a negative run differential. Down to their final three outs and held to just two hits by Ramirez through eight, the Orioles struck for a pair in the ninth to tie the game 2-2 on a Chris Davis single off Wilhelmsen.

Mariners manager Eric Wedge had allowed Ramirez to take the mound in the ninth with a pitch count at 95. Ramirez promptly allowed singles to Robert Andino and Nate McLouth on the first two pitches he threw before Wilhelmsen entered the game.

"I just tried to be aggressive with the hitters in the ninth and get ahead in the count," Ramirez said. "But I didn't have good luck in the ninth at all. That's what happens and it's something I need to learn about. Of all the innings, the ninth is the toughest one."

Ramirez said he feels pleased at being able to finish strong if this was indeed his last start. The Mariners had only planned to give him a pair this month and might return him to relief work the final two weeks of the season.

Seattle might need a few extra bullpen arms by the time this week is done. A second-inning implosion by Hector Noesi on Monday pressed the bullpen into extended use, and then the inability of anyone to score Tuesday night dragged this contest out far longer than anyone anticipated.

"It's tough on both sides offensively," Wedge said. "Everybody wants it so bad. I mean, we had so many opportunities. We had so many opportunities where with one hit, the game was over."

But nobody delivered.

Instead, it was up to the relievers — working their second straight night of seven-plus innings — and Olivo to keep things alive.

"Miguel Olivo is as tough as they come," Wedge said. "His drive and his heart and his intensity, it's second to none. The guy takes tremendous care of himself and cares as much as anybody.

"You feel for all of your guys, but the guy back there catching 18 innings and fighting through it all, you feel for him."

Olivo said he got through it by keeping his mind occupied on his pitchers.

"I tried not to call the wrong pitch," he said.

But Baltimore finally broke through in the 18th when McLouth drew a leadoff walk, followed by a J.J. Hardy single that put runners at the corners with none out. Pinch-hitter Teagarten then singled to bring home the decisive run and an ensuing run scored when third baseman Chone Figgins bobbled a grounder and had to settle for an out at third rather than throwing home.

"Everybody had energy," Olivo said. "They were cheering for everybody, rooting for everybody to try to win the game. We had a lot of opportunities to win the game, but it didn't happen."

Geoff Baker: 206-464-8286 or gbaker@seattletimes.com. On Twitter @gbakermariners. Read his daily blog at www.seattletimes.com/Mariners.