NEW YORK -- In the process of closing out one of the most pressurized saves of what has been a career-defining season for him, Cardinals reliever Ryan Helsley showed off his complete control of Saturday’s ninth inning by relying not on his triple-digit fastball, but instead a steadily improving slider.

To notch the game-ending strikeout and preserve the Cardinals’ 6-5 victory over the Yankees with the potential tying and winning runs on base, Helsley outwitted rookie catcher Austin Wells in the most unorthodox of ways. He gave Wells one look at his 100.8 mph fastball early in the count, but then ended the at-bat with sliders that came in slow (91.7 mph), slower (90.4 mph) and the slowest (87 mph). That final slider induced the swing and miss from Wells that the Cardinals needed in a game that turned into a nailbiter following a frantic eighth inning.

“The differential there in speed is huge, and that makes [Helsley] really tough when he lands that [slider],” Cardinals manager Oliver Marmol marveled. “He’s been good all year. This guy is continuing to grow, and regardless of stage or moment, he’s done a really nice job of locking it in and being present. So it was another great example of that.”

Helsley’s MLB-leading 42nd save in 45 tries also helped the Cardinals secure a bit of history. The victory was their first at the new Yankee Stadium (2009-present, the last team to do so) and their first over the Yankees in the Bronx since Game 5 of the 1964 World Series (Oct. 12, 1964). Coincidentally, St. Louis’ winning pitchers in 1964 and 2024 were both named Gibson -- Bob in 1964 and Kyle on Saturday. Also, the play-by-play voices were both named Caray -- Harry 40 years earlier and Chip on Saturday.

“When I heard about the Gibson thing, that’s pretty cool,” said Kyle, who saved an authenticated ball from the game to present to his father, Harold.

When reminded that Hall of Famer Bob Gibson pitched 10 innings in that 1964 victory -- three innings longer than Kyle on Saturday -- Marmol cracked, “I pulled him too soon.”

Marmol pulled Gibson largely because he trusts what he has in the bullpen with Helsley, who became an All-Star for the second time in his career this season after notching a team-record 32 saves before the break. His save percentage (93.3 percent) ranks first in MLB, and he moved a step closer to Trevor Rosenthal’s club record of 48 saves in 2015. Helsley admitted that the club record for saves is a goal this season because it means the Cardinals are winning games.

“I’ve never been one to chase personal stats, but that’s one that would be really cool,” said Helsley, who joined Hall of Famers Bruce Sutter and Lee Smith as the only Cardinals relievers with multiple All-Star Game appearances. “Maybe at the end of the season, I can look back and say I got that [club record], but if not, I don’t think it’s a failure by any stretch. To be up there now with some Cardinals greats -- and Rosenthal had a great career with the Cardinals, too -- and be up there with [Jason Isringhausen], Sutter and Smith, it’s pretty surreal to me.”

For most of Saturday, it didn’t look like Helsley would be needed to preserve a Cardinals win. Brendan Donovan hit a three-run homer to key a four-run third inning, and Gibson pitched seven strong innings as the Redbirds stormed to a 6-1 lead. After New York cut it to 6-2, pinch-hitter Giancarlo Stanton came within inches of tying the score with a drive off the center-field wall that cleared the bases.

In the ninth inning, Helsley retired the first two batters before Yankees superstar Juan Soto turned around his 101.5 mph fastball with a 114.3 mph rocket into the right-field corner for a double. Following a no-brainer of an intentional walk to Aaron Judge, Helsley went to work on Wells.

Arguably the game’s best closer threw three different pitches to open the at-bat -- slider in the dirt, four-seam fastball and curveball. To end it, Helsley countered with three straight sliders, and Wells swung over the last one to end the game.

Gibson, one of Helsley’s best friends on the team, appreciated the sophistication that Helsley showed by using his finesse pitch -- rather than the triple-digit heater -- to outwit the hitter.

“Hels and I have spent a lot of time getting breakfast and getting coffee, and it’s been fun to talk pitching with him this year,” Gibson said. “He has so much pitchability. He has so much confidence in his slider, his curveball is nasty, and he can keep you guessing as to when the 102 [mph] is coming. You expect the express every time, and you just never know when you’re going to get the 3-2 slider.”