SEATTLE (AP) Logan Morrison had a pretty good angle from his vantage point and thought the ball would land fair inside the right-field line.
From the dugout, Mariners manager Lloyd McClendon didn't know for sure.
Running toward first, Austin Jackson wasn't certain, either.
An emphatic signal by first base umpire Jeff Nelson soon let everyone know Jackson had delivered in the clutch.
Jackson's bases-loaded single scored Morrison from third to give Seattle a 6-5 win over the Baltimore Orioles in 10 innings Tuesday night, marking the first time since baseball expanded to 30 clubs that all 15 home teams won on the same day.
''I really didn't know,'' Jackson said. ''I still didn't know if it was fair even when he called it. ... Nobody really reacted. I guess it hit the chalk and the rest is history.''
Nelson Cruz and Mark Trumbo homered for the Mariners. Cruz extended his hitting streak to a career-high 21 games, matching Troy Tulowitzki for the longest streak in the majors this season, but exited before the seventh with neck spasms.
''I think when you have a Nelson Cruz sitting there in the middle of your lineup, you feel pretty confident going into every game,'' Jackson said. ''He's swinging the bat. We're rallying behind him ... trying to feed off that energy.''
Orioles catcher Matt Wieters left early with a strained right hamstring.
Jackson's hit ended a back-and-forth game. The Mariners overcame a first-inning deficit before relinquishing the lead on two quick homers by Baltimore in the eighth.
The last time home teams went undefeated on a day with more than one game was an 8-0 record on Aug. 28, 2008 - although road squads were 7-0 on April, 2, 2013, according to STATS.
Arizona and Tampa Bay joined the majors in 1998, bringing the total to 30 teams.
STATS said previously the best performance by home teams had been 11-0, accomplished six times - three in the 1800s. The most recent occasion was Sept. 16, 1989.
Morrison led off the 10th with a bloop double down the left-field line. Brad Miller followed with a single that put runners at the corners. A walk to Mike Zunino set the stage for Jackson, who won it against reliever T.J. McFarland (0-2).
''I don't want to be the guy that gives that up after a game like that, playing our hearts out,'' McFarland said.
Fernando Rodney (5-4) pitched a perfect inning.
Adam Jones and Chris Davis hit back-to-back homers to tie the game in the eighth. Jones' two-run shot chased reliever Tom Wilhelmsen. Davis greeted Joe Beimel with a towering drive to right that made it 5-all.
Seattle had a 4-2 lead after the first thanks to two homers. Cruz hit a solo shot with two outs and Trumbo added a three-run drive later in the inning.
Kyle Seager added another run for Seattle with a second-inning sacrifice fly to score Miller, who doubled leading off the inning and moved to third on Jackson's single.
The Orioles took a 2-0 lead in the top of the first on a two-run single by Jonathan Schoop.
Baltimore loaded the bases with two outs before Schoop's hit, but Mariners starter Taijuan Walker quickly rebounded and later retired 11 straight.
Walker allowed two runs in six innings. He struck out six and walked one.
Chris Tillman gave up five runs and eight hits over 2 1-3 innings in an unusually rough outing against the Mariners. The former Seattle second-round draft pick entered 6-0 with a 2.09 ERA in seven career appearances against his former club.
Tillman was struck on the back of his right arm by a line drive off the bat of Robinson Cano in the first inning. After a brief delay and a few warmup pitches, Tillman was cleared by a trainer to continue.
The right-hander didn't think it affected his performance much.
''It might have a little bit, but not enough to make that big an effect on the quality of my pitches,'' he said.
Orioles: Wieters came out during a pitching change in the third. He said his hamstring felt sore the past few games and it was worse during his first at-bat. He will be re-evaluated Friday after Thursday's off day, but believes the injury was caught in time to avoid the disabled list. ... RHP Chaz Roe is expected to get a cortisone shot for his shoulder inflammation, but is still on track to return from the disabled list Aug. 25, manager Buck Showalter said.
Mariners: Cruz said he hopes to play Wednesday. ... LHP Charlie Furbush (biceps) is not quite ready to begin a rehab assignment and will throw another bullpen Saturday with the team in Boston. The reliever has no structural damage, but does feel a slight pinching sensation when he throws.
Orioles: Baltimore wraps up a nine-game road swing, sending Kevin Gausman to the mound looking to improve his 2-3 record and 4.56 ERA.
Mariners: RHP Hisashi Iwakuma pitches Wednesday afternoon against Baltimore as the Mariners close out a six-game homestand.