SEATTLE -- Despite the many huge moments in his young career, Julio Rodríguez still had another major milestone he badly wanted to clear.

His glistening résumé already includes a Home Run Derby record, two All-Star Game selections, a designation as the fastest player in franchise history to 50 homers, a 30/30 season at just 22 years old and more. Yet for all those feats, he’d never been in the batter’s box on the winning end of a walk-off hit, even in the Minors.

Until Saturday.

Rodríguez ripped a 3-1 sweeper from Red Sox reliever Justin Slaten into shallow right field that easily scored Josh Rojas from third base, sent Seattle to a 4-3 win in the 10th inning and helped salvage Logan Gilbert's stellar start after the Mariners went down by two runs in the top of the frame.

How much was the milestone on his mind?

“I know -- trust me,” Rodríguez said. “I feel like we’re all, as baseball players, we all want to come through in that situation for the team and just kind of send it off. It felt pretty good to finally have my first one.”

Rodríguez has had clutch moments in the past -- the 117.2 mph game-tying homer in the ninth inning against the Braves, the go-ahead homer after a benches-clearing incident in Houston, both in 2022 -- but Saturday’s walk-off carried weight within the context of his efforts to be more disciplined in high-stakes situations.

“If you do slow it down and control your emotions like he did tonight, great things can happen,” Mariners manager Scott Servais said. “That's not going to be the last walk-off hit he gets, that's for sure.”

This was the type of moment that Rodríguez badly wanted to deliver during his second season, but in many of those instances, he admittedly succumbed to an undisciplined and free-swinging approach. It was those specific shortcomings that led him to call the 2023 season “a sophomore slump,” despite finishing fourth in the American League MVP Award vote.

“I feel like it's definitely been a working process to be able to stay with it, stay within myself, stay with my plans,” Rodríguez said. “And I feel like this year, that's definitely going to be one of my focuses. ... Let everything play out after that, and not really focusing so much on the results and how to get to the results. I feel like that's something that I'm looking forward to keep doing throughout the whole year.”

In Saturday’s sequence, Rodríguez worked into a hitter’s count, but he was prepared to lay off and pass the baton -- much like he did on a six-pitch walk the night prior, which Servais said was “the best at-bat in the game” and “a sign of a young superstar maturing.” Laying off loaded the bases with two outs while the Mariners were clinging to a one-run lead.

“In that moment, I was really curious,” Servais said. “We saw that moment come up a lot last year. And he would swing at that 3-2 pitch, or maybe that 2-2 pitch that was just off [the plate] and he maybe wouldn’t get his best swing off because it was not a strike.”

But Saturday’s sweeper from Slaten, who was making his Major League debut, was just high enough for Rodríguez to drive despite a late drop to the bottom of the zone, and he did so over everyone’s heads with the infield in.

“I knew that they'd been throwing a lot of spin balls to us,” Rodríguez said. “So, seeing him up and just kind of staying to the middle and not trying to do too much.”

Rodríguez was Saturday’s hero, but those who preceded him were just as vital.

Luke Raley blooped an RBI single to score automatic runner Ty France, then Raley advanced to third on a single by Rojas and scored on a fielder’s choice from J.P. Crawford, whose dribbler forced Boston second baseman Enmanuel Valdez to throw home, but not in time.

The Mariners had just four walk-off wins in 2023, tied for the fewest in the AL with their divisional counterparts in Texas and Houston. And Saturday marked the first time they won after trailing by two or more in extras since an 8-7 win over the A's on May 3, 2009.

The offense’s late efforts -- despite 12 strikeouts -- salvaged the stellar start from Gilbert, who was arguably just as masterful as George Kirby the night prior. Seattle’s towering righty surrendered just one run on four hits and one walk over seven innings.