Six relievers limited Seattle to just one hit over the 6 2/3 innings, and David Murphy had a two-run single in the Indians' three-run 12th to beat the Mariners 6-3 Sunday.
"Now that was impressive," Francona said. "Any time you're on the road you're always one pitch away (from losing)."
Murphy's bases-load hit with two outs helped Cleveland take three of four from the Mariners and get its 10th victory in 13 games.
"I can sit here and analyze it all I want," Mariners manager Lloyd McClendon said. "The fact is we got five hits in 12 innings. You are not going to win. We've got to swing the bats."
Indians second baseman Jason Kipnis had two doubles to finish May with 51 hits to go with 37 runs. He's the first player since Philadelphia's Jimmy Rollins in 2005 to go 50/30 in one month.
"In a four-game series, day game after a night game, it kind of a battle of wills and a battle of the bullpens," Kipnis said. "First, give credit to the bullpen. They stayed after it, we kept putting pressure on them and finally broke there at the end.
"The way we did it is much better," Kipnis added. "We did it with a win in an extra-inning game. The 50 hits is lot of hard work coming to fruition, paying off in the cages. The 30 runs (are) just a credit to the team, them driving me in."
Francona said Kipnis had "an unbelievable month. But forget the month, I think he's an unbelievable player. He does so many things to help us win. It's been like that for a while now. He's been a force."
Lonnie Chisenhall opened the 12th with a walk off Dominic Leone (0-4), the eighth Mariners pitcher used. With one out, Jose Ramirez doubled off first baseman Logan Morrison's glove. Chisenhall advanced to third.
"I've got to make that play," Morrison said. "I'm on the line for a reason, no doubles."
Kipnis was intentionally walked, loading the bases. Michael Brantley drew a two-out walk to force in the tiebreaking run. Murphy followed with his hit to add to the lead.
The Indians played the game under protest because of a disputed third out in the 12th.
Zach McAllister (1-2), who worked one inning, picked up the win. Austin Adams finished the 12th to earn his first career save.
"I think as a bullpen guy, no matter what type of pitcher you are, you like to compete," McAllister said. "You like to be out there with the game on the line and hopefully be successful at it."
Brandon Moss had four hits for the first time this season and fifth time in his career. Ryan Raburn had a solo shot in the sixth, his third.
The Indians had a season-high 18 hits and left a season-high 17 runners on base.
Seattle scored three runs in the fifth on a throwing error by third baseman Mike Aviles, a single by Austin Jackson and a sacrifice fly by Robinson Cano.
Mariners: RHP Hisashi Iwakuma (strained lat), on the DL since April 24, threw catch from 90 feet Friday. He could be on the mound by the end of the week.
Indians: INF Carlos Santana came off the restricted list Sunday after missing three games to be with his wife Brittany, who gave birth Thursday morning to a girl. To make room, OF Jerry Sands, who hit a two-run home run Saturday, was returned to Triple-A Columbus.
Mariners: RHP Felix Hernandez (8-1, 1.91) starts against the Yankees on Monday night. Since 2009, he is 8-2 with a 2.11 ERA in 13 starts, with four complete games, against them. Hernandez leads the league in wins, whip (0.89) and is third in ERA and strikeouts (71).
Yankees: RHP Michael Pineda (6-2, 3.36) will be facing his former team for the first time since his 2012 trade to New York.
MERRY MONTH OF MAY
Kipnis is the ninth Indians player since 1914 to go 50/30 in a month, and the first since Jeff Heath in August 1938. He also is the first Indians player ever to have 50 hits in May.
The Mariners need a starter Tuesday against the Yankees after LHP James Paxton (strained finger tendon) was placed on the DL Friday. It could be LHP Mike Montgomery from Triple-A Tacoma. He was scratched from his start Sunday. McClendon was non-committal. Montgomery is a former first-round draft choice of the Kansas City Royals who has bounced around the minors. He is 4-3 with a 3.74 ERA for Triple-A Tacoma.