SEATTLE -- The Boston Red Sox will be the cheerier and better-rested team when they open a series against the Seattle Mariners on Monday night at Safeco Field.

The Red Sox capped a four-game split against the Los Angeles Angels on Sunday afternoon, scoring five times in the ninth inning for a 5-3 win at Anaheim, Calif.

The Mariners then played -- and blew -- the nationally televised Sunday night game at Wrigley Field.

Seattle built a 6-0 lead through three innings thanks to a trio of two-homers, then watched the Chicago Cubs slice into the deficit and eventually tie the game 6-6 with three runs in the ninth. The Cubs won 7-6 in 12 innings when left-handed pitcher Jon Lester, appearing as a pinch hitter for the first time in his career, dropped down a game-ending squeeze bunt on a 2-2 pitch.

As a result of the late developments, the Mariners' bullpen might be short-handed Monday night. Five Seattle relievers pitched a combined 6 1/3 innings, with closer Steve Cishek blowing a save for the sixth time in 31 chances and Cody Martin (1-1) taking the loss.

The appearance on "Sunday Night Baseball" was the Mariners' first since 2004, and the game wound up being unforgettable for the wrong reasons, at least from a Seattle perspective.

"It's disappointing. I thought we had the game in hand," Mariners manager Scott Servais said.

The arrival of the Red Sox in Seattle means the last visit of David Ortiz, and Mariners fans won't be too sad to say goodbye.

Since 2013, Ortiz has hit .444 with four home runs and nine RBIs in 10 games played at Safeco Field. The Mariners have tried everything to negate the offense of the future Hall of Famer, with seven free passes being the only effective way they have found to quiet his bat in that span.

The 40-year-old designated hitter is not showing any signs of slowing down. Ortiz enters Monday's series opener with a .320 batting average as he continues to put up one of the best offensive seasons of his prodigious career.

Ortiz and the Red Sox (57-46) have more pressing issues than saying goodbye, though. Even after the ninth-inning rally Sunday, Boston is 1 1/2 back in the American League East standings after seven of its past 10 games.

The Red Sox were losing ground in the division race and were losing their grip on the wild-card standings before scoring five runs -- four on back-to-back, two-out homers from Dustin Pedroia and Xander Bogaerts -- in the ninth to beat the Angels.

"It was pretty awesome," Bogaerts told MLB.com. "After all we've been through these past few days, it was definitely nice to have this one today."

The Mariners have seen their once-promising postseason hopes go in the tank since the beginning of June, and the recent slide put Seattle into the position of being a seller at the trade deadline. The Mariners dealt relievers Mike Montgomery and Joaquin Benoit last week, then sent starter Wade Miley to Baltimore on Sunday.

"This decision is the best move for the Mariners' present and future," general manager Jerry Dipoto said of the Miley trade, which netted minor league left-hander Ariel Miranda.

The Mariners plan to send left-hander James Paxton (3-5) to the mound Monday, while left-hander Eduardo Rodriguez (2-4) is scheduled to start for the Red Sox.

The more intriguing pitching question is who might finish the game for Boston, as closer Craig Kimbrel is scheduled to join the team Monday in Seattle. Kimbrel underwent knee surgery July 11 to repair a torn left medial meniscus, and he could be activated any day now.