OAKLAND -- Sonny Gray recently got his first taste of pitching with the birds on the bat across his chest in front of his new home crowd at Busch Stadium, but he also savored the opportunity to pitch at the ballpark that he called home in the early days of his career.

And as fate would have it, he achieved his latest career milestone right where it all began.

Gray earned the 100th win of his Major League career in Monday's 3-1 win over the A's at the Coliseum -- where he also picked up his first win more than 10 years ago -- on Jackie Robinson Day. Working within the confines of a 75-pitch limit, Gray dealt across six scoreless innings, striking out six while scattering four hits.

He joins current rotation mates Lance Lynn and Kyle Gibson in the group of 13 active pitchers who have reached the century mark in wins.

"To get his first win here, 100 here, it's pretty cool," manager Oliver Marmol said.

After signing a three-year, $75 million deal to join the Cardinals in the offseason and missing the beginning of the season with a right hamstring strain, Gray has been as advertised -- or better -- in his first two starts with St. Louis. He has yet to issue a walk across 11 scoreless innings.

Gray made his Major League debut with the A's in 2013, making three appearances (one start) on the road before picking up that fateful first win. A 23-year-old rookie at the time, Gray blanked the Astros over eight innings on Aug. 15, 2013, in his first start in Oakland.

Although he's only been back three times as a visitor since being traded to the Yankees at the 2017 Trade Deadline, Gray's shadow looms large in Oakland. He is the leader in wins (27), innings (402 1/3) and strikeouts (334) at the Coliseum among all active Major League pitchers.

And Monday was likely the last time that Gray will take the mound at the Coliseum, as the A's recently agreed to a three-year deal to play in Sacramento until the team's planned relocation to Las Vegas.

"This is the team that drafted me," Gray said. "This is the team that gave me a shot. This is the team that believed in me. This is the fans who helped shape my career.

"I always enjoy coming back here, especially coming back here as a visitor now and listening to other players and being like, 'Dude, I love it.' And they're like, 'What?' And I'm just like, 'Man, you just don't know it like I know it.'"

Among his favorite memories from his tenure in Oakland, Gray recalled the time his firstborn son, Gunnar, met A's mascot Stomper, a moment captured in photos that are still on display in the family's home. He mentioned the drummers in the right-field bleacher seats alongside some of his own career highlights, such as taking a no-hitter into the eighth inning on Opening Day 2015.

That's not to mention the success that Gray and the A's enjoyed early in his tenure with the team. Following his Major League debut in 2013, Gray was a key part of the stretch run as Oakland captured the American League West.

With 10 big league starts to his name, Gray was called on in some critical spots in the postseason that year, drawing two starting nods at home against Tigers ace Justin Verlander in an AL Division Series that the A's lost in Game 5.

"I got to see the best sides of it," he said. "I got to see the sellouts, and winning the divisions, and going to the playoffs, and playing in the playoffs here."

Gray's time with the A's made him the pitcher he is nowadays, and the Cardinals like what they're seeing so far. His teammates were aware of what pitching at the Coliseum meant to him, too.

"Before the game, I was helping him to slow down because he had a lot of emotions, obviously," catcher Willson Contreras said. "This was his house for many years."

While Gray's spotless ERA won't last forever, the hope is that his passion for the game and presence on the mound can give the entire team a jolt of energy.

And in a small sample of two starts, he's done just that.

"You sign him for a reason, and then he goes out there and does exactly that," Marmol said. "It gives everybody around him confidence."