Back in December, the Athletics handed Luis Severino the largest guaranteed contract in franchise history—a three-year deal worth $67 million. Just one game in, that investment already is paying dividends.

Severino dazzled the Seattle Mariners in six innings of scoreless ball Thursday in the A's 4–2 loss at T-Mobile Park. In those six frames of work, Severino allowed three hits and four walks but didn't yield a single run while also notching six strikeouts. And one of those strikeouts featured one of—if not —nastiest pitches of this young 2025 season.

With two runners on base and two outs in the sixth inning, Severino worked a 2-2 count against Seattle slugger Rowdy Tellez. After Tellez fouled one off, Severino froze him with an absolutely lethal backdoor sweeper. The pitch started well outside the zone but broke in, settling into catcher Shea Langeliers's mitt right on the outside corner.

"I knew I had enough in my back pocket to reach back and throw some nasty pitches,” Severino told MLB's Martin Gallegos after the game. “In my head, that was my last hitter. So, I was like, ‘I’m going to throw everything I’ve got.’ I just wanted to throw the nastiest stuff that I had.”

Langeliers agreed with the right-hander's assessment.

"Going back and watching it, it got back to the zone, but it felt like it would have hit a right-handed hitter,” the catcher said. "That’s how far out to my left it was, and then it came all the way back. It was crazy. … I would say that’s up there for the nastiest pitch I’ve ever caught."

The A's would go on to lose that game 4–2 on Opening Day but rebounded for a 7–0 win on Friday.