ARLINGTON -- Standing in the batter’s box with the bases loaded and an 0-2 count against Shohei Ohtani would be nerve-racking for any player, regardless of caliber.

Rangers backup catcher Jonah Heim wasn’t fazed. After swinging strikes on the first two pitches -- a curveball and a splitter -- Heim sat back, and with another splitter in the heart of the plate, drove a 391-foot grand slam into the right-field stands off of the reigning American League MVP.

Heim’s grand slam was his first career hit against Ohtani and gave the Rangers a lead they would not relinquish in Thursday night’s 10-5 win over the Angels at Globe Life Field.

“I was a little jacked up on my first few swings, just trying to do a little too much,” Heim said. “I kind of backed out of the box and took a deep breath and calmed down. I was just trying to just keep the line moving, put the ball in play, barrel something up and get [Brad] Miller up there. So luckily, [Ohtani] hung it a little bit and I put a good swing on it.”

"I thought I threw a couple good splitters and non-good splitters," Ohtani said through interpreter Ippei Mizuhara. "Obviously, the one I gave up just hung up there."

It was an at-bat full of firsts when Heim and Ohtani faced off in the second inning. Yes, it was Heim’s first career grand slam, but it was also the first Ohtani had surrendered. Coming into Thursday, opponents were 0-for-58 with 41 K's against 0-2 splitters from Ohtani. Heim’s grand slam was not only the first hit in that situation, it was the first home run off Ohtani’s splitter.

It was also the first grand slam by a Texas catcher since Bobby Wilson on May 14, 2016. Wilson, ironically, played for both the Rangers and Angels during his 10-year big league career and is currently Texas’ catching coach.

And Heim wasn’t done there. He finished the day 3-for-5 with five RBIs. After going 0-for-6 against Ohtani in 2021, the catcher went 2-for-2 with all five RBIs coming against the right-hander Thursday.

“It’s pretty special,” Heim said. “When you can hit a grand slam -- just a home run off a guy as talented as Ohtani -- it’s special. I’m excited, hopefully we can get them tomorrow. I think it was the same approach [as last year]. I’m just trying to keep it simple: put some good swings on it, just hit the barrel and whatever happens from there, happens from there. Just trying to barrel up Ohtani’s stuff. When you put some good swings on and get some barrels, good things will happen. That was kind of our approach today.”

Heim has a way of coming up in big moments. In 2021, his first season with the Rangers, Heim knocked back-to-back walk-off home runs against the Mariners. Texas manager Chris Woodward said a big part of Heim’s success in those moments is that he’s not afraid to stick to a game plan, whatever that may be.

“He just has no fear in those moments,” Woodward said. “And he has no fear in following a game plan. He says, ‘This guy's throwing 100 miles an hour, I'm gonna be on his fastball.’ He'll go up and do it. [Last year] he just couldn't execute. His swing was a little bit back and forth, it was a little off at times last year. I think where he's at now is a lot more consistent. … But there's no fear of getting a swing off.”

In just three games this season backing up starter Mitch Garver, the consistency is paying off. Heim is 6-for-11 with two home runs, eight RBIs and no strikeouts. Heim said he feels a lot more confident this season, coming in with a clear, defined role and understanding it within the team.

Heim added that he feels like he’s grown a lot after a long spring competing for the backup catcher spot with Jose Trevino, who was ultimately traded to the Yankees.

“With the new hitting coaches that came in Donnie [Ecker] and Tim [Hyers], they've been outstanding,” Heim said. “We've made some adjustments to the swing, and just really sticking to our game plan and going from there. When I'm confident, it's when I'm at my best, obviously like everybody else. I’m just trying to keep the confidence up and just put some good swings on some balls.”