LOS ANGELES -- As they got down to the final week of Spring Training, the D-backs faced some final roster decisions.

They had to decide what to do about the fifth-starter race between Ryne Nelson and Drey Jameson, as well as the final position-player spot, with Kyle Lewis and Pavin Smith the primary candidates.

In the end, the D-backs went with Nelson, but surprised some by keeping Jameson as a reliever. And they chose Lewis based on his torrid spring at the plate.

Both decisions paid big dividends Friday night as Jameson threw four outstanding innings of relief and Lewis delivered a pinch-hit, two-run homer as the D-backs beat the Dodgers, 2-1, at Dodger Stadium.

Let’s start with Jameson, who had not pitched in relief since his days at Ball State University. But when manager Torey Lovullo told him he had made the roster as a reliever, he was all in on making the adjustment.

Friday, with Merrill Kelly nearing the bottom of his gas tank at 74 pitches with runners at first and second and two outs in the fourth, Lovullo summoned the rookie from the ’pen.

“It’s a little different,” Jameson said of the relief role. “You’ve got to get ready a lot faster. You're sitting down there, you don't know. So the adrenaline is not really there and then you hear your name and you’re like, ‘Oh crap,’ and you’ve got to get going. And then when you’re running out to the mound it’s a little bit of a different adrenaline.”

Jameson showed zero nerves on the mound as he allowed just a pair of hits -- one of which was a Mookie Betts’ homer, over four innings.

“He really controlled the game,” Lovullo said. “And we won this game because of Drey Jameson.”

With help from Lewis, of course, whom the D-backs acquired in an offseason deal with the Mariners. He is expected to get starts at DH against left-handers.

Lewis hit leadoff for the D-backs on Opening Day against southpaw Julio Urías, and went 0-for-4 with three strikeouts. Friday, with a right-hander on the mound for the Dodgers, Lewis was on the bench to start the game.

As the innings wore on, he would go down to the batting cage and take some swings to try to stay hot and ready, checking the lineup to see when a pinch-hit spot might roll around for him.

When the D-backs saw left-hander Alex Vesia begin warming up in the seventh inning, Lewis began talking with hitting coaches Joe Mather and Damion Easley about how he would approach an at-bat against Vesia.

“I kind of had my eye on maybe slider down and in,” Lewis said. “They’ve been kind of attacking me that way. So I just wanted to see if I can get short with my swing.”

After Evan Longoria pinch-hit and doubled with one out, Lovullo sent Lewis up to hit for Josh Rojas and Vesia missed with a slider down before coming down and in with a slider. Lewis fouled it off and then took a high fastball to run the count to 2-1.

Vesia then tried to go down and in with another slider, but left this one up and Lewis crushed it into the left-field bleachers.

“Just trying to be short to the ball, trying to be simple to it and just try to compete honestly, try to compete, have a competitive at-bat, keep the line moving the best I could. And especially after Longo put the double down in the corner it was cool to follow that up and get us two runs.”

Spring Training statistics may not count in the regular season, but as Friday night showed, decisions made at the end of camp can pay big dividends.