MIAMI -- Relax and concentrate.
That's what Seattle pitching coach Rick Waits told right-hander Yoervis Medina during his mound visit with the bases loaded and no outs in the ninth inning of Friday night's game.
Easier said than done when baseball's RBI leader steps up to the plate.
Three pitches later, Medina surrendered a walk-off grand slam to Giancarlo Stanton in an 8-4 loss to the Marlins in front of 21,388 at Marlins Park.
Stanton, who drove in five of Miami's eight runs, connected on his sixth homer of the season on a 1-2 slider, sending it to left-center. Earlier in the game Seattle had intentionally walked him twice.
"It's just the way it goes unfortunately," Mariners manager Lloyd McClendon said. "We really tried to stay away from him all night. He's the one guy in the lineup that can really hurt you. We had no choice there."
Pinch-hitter Reed Johnson singled and Christian Yelich bunted for a hit to open the ninth. Medina (0-1) fielded Marcell Ozuna's sacrifice bunt and threw to third for the forceout, but a challenge overturned the call because third baseman Kyle Seager bobbled it on the transfer.
"We've seen it happen a couple of times already this year, so I know the rule," Seager said. "I knew that was what he was coming out to do, but I felt like I caught the ball on the base and I tried to transfer it over there to try and make a throw to first. That's when I bobbled it."
Chris Young, who opened the season with eight scoreless frames over his first two outings, allowed four runs on seven hits in just three innings.
Miami scored a pair of runs on three hits in the first. Ozuna doubled to straightaway center with one out and Stanton singled him in. Stanton moved to second on a wild pitch and came home on Casey McGehee's two-out RBI single to left. Young escaped further damage with runners at first and second when Derek Dietrich flied out to left.
The Mariners capitalized on a fielding error for a pair of unearned runs off Nathan Eovaldi in the second. Michael Saunders singled to center before Seager flied out to deep center. Dustin Ackley singled to right. Stanton, who charged the ball, saw it bounce over his glove and roll to the wall as both runners raced home.
The Marlins regained a 3-2 lead on Ozuna's sacrifice fly to center with one out, but bailed Young out with aggressive baserunning.
Adeiny Hechavarria led off with a walk and got caught stealing. Eovaldi followed with a single to right and advanced to third on Yelich's single. That set up Ozuna's sixth RBI of the season.
Young intentionally walked Stanton. On Garrett Jones' half swing that went to the hole at short, Brad Miller fooled Yelich, who began to round third. Miller threw home rather than first, nabbing Yelich in a rundown.
Jarrod Saltalamacchia blasted a one-out homer in the third off Young, extending the lead to 4-2. His 473-foot blast came on a 2-0 pitch that was sent halfway up the upper deck.
"I didn't do my part tonight," said Young, who threw 73 pitches in his second start of the season. "Bullpen did a great job, the hitters kept fighting and had quality at-bats to try and pick me up. I wish that I could've given a better effort and helped this team win the game. I believe in the character we have in this club, and I think we'll bounce back and rebound from this."
Miller trimmed the deficit to 4-3 on an RBI groundout to first in the fifth. It followed Abraham Almonte's leadoff triple to center.
Down by a run in the seventh, Corey Hart produced a two-out RBI single off reliever A.J. Ramos.
Almonte doubled with one out and moved to third on Dietrich's fielding error. With runners at the corners, Robinson Cano struck out against southpaw Mike Dunn. Ramos entered the game to face Hart, who reached out for an 0-2 pitch.
Until Stanton's homer, Seattle's bullpen had pitched five scoreless innings. Though the Mariners came back from two runs twice, they stranded a runner at third in both the sixth and eighth innings. Marlins closer Steve Cishek (1-0) pitched a perfect ninth for the win.
After opening the season 6-3, Seattle has dropped six of seven, including four in a row.
"We're in one of those spots where little things obviously aren't going our way, but we're in every ballgame, so the confidence is still there that we're a good ballclub," said Hart, who went 2-for-5. "It's just when it comes down to some of these situations, we need to come through with what we're lacking. You're going to go through stretches like this. It's early enough where you can't get too down because there's a lot of baseball to play."
Christina De Nicola is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.