GLENDALE, Ariz. -- More than the fastball that sat at 98 mph or the three shutout innings, the story of Roki Sasaki's debut as a Los Angeles Dodger on Tuesday night was best told through the words of the hitters facing him.

"Nasty," Austin Hays said.

"Heavy," TJ Friedl said.

"Electric," Austin Wynns said.

Sasaki more than earned the praise from the three Cincinnati Reds veterans with 17 combined major league seasons and their future Hall of Fame manager, Terry Francona, who called the 23-year-old's first spring training outing in a Dodgers uniform "impressive."

Sasaki, who signed with the Dodgers in January after a lengthy recruiting process in which he chose them over the San Diego Padres and Toronto Blue Jays, struck out five in the team's 4-2 win at Camelback Ranch. Two weeks before the Dodgers kick off the 2025 MLB season in Japan, where he starred for the past four years with the Chiba Lotte Mariners, Sasaki reinforced why Los Angeles is comfortable starting him in the second game of such a high-profile series.

Beyond his high-octane fastball, which peaked at 99.3 mph, Sasaki unleashed a split-fingered fastball that evaluators believe is among the best in the world -- and generated seven misses on eight swings.

"Some break straight down, some go to the left, some go to the right," Dodgers manager Dave Roberts said. "So it is tough to square it up. You just don't know what it's going to do."

Sasaki, who entered the game after a four-inning start by countryman Yoshinobu Yamamoto, shook off a shaky start in which he gave up a hard-hit single to Wynns and followed with a 97 mph fastball to the gut of Stuart Fairchild, who was squaring to bunt. Sasaki then struck out two Reds regulars, Friedl and Matt McLain, staring at splitters.

"The splitter was like two different splitters from what I saw," Friedl said.

Sasaki signed with the Dodgers for a $6.5 million bonus in January -- a fraction of what he would have earned had he waited two more years and come to Major League Baseball as an international free agent -- and has spent spring training trying to fine-tune his stuff, particularly the fastball that has peaked at 102.5 mph but lost oomph last year. Time spent in the Dodgers' pitching lab helped Sasaki with his mechanics. While he said he felt a combination of excitement and nervousness before entering the game Tuesday, he focused once he reached the mound.

"Today's the fruit of all the hard work that I put in during the offseason and the first part of spring training," Sasaki said through an interpreter.

A leadoff double from All-Star shortstop Elly De La Cruz, a walk to Christian Encarnacion-Strand and a wild pitch left Sasaki facing trouble in the sixth, but he induced a popout from Noelvi Marte to conclude the inning. Two more strikeouts in a hitless seventh ended his night on 46 pitches, 26 of which were strikes.

"We're going to continue to learn more from Roki," Roberts said. "And obviously he's pitched in a lot of big games in his career, but you're also in an environment where he's comfortable. This is something that's all new to him. And so he's learning on the fly and we're asking a lot of him, but there's a lot of confidence supporting him."

Roberts called it a "good night for the Dodgers," who added Cy Young winner Blake Snell to a rotation that already included All-Star Tyler Glasnow and will later add future Hall of Famer Clayton Kershaw and Shohei Ohtani, who is returning from his second Tommy John surgery. Surrounded by stars, Sasaki still will get the ball March 19 against the Chicago Cubs, one day after Yamamoto opens the season.

Sasaki will start in his final outing of the spring on March 11, Roberts said, before the highly anticipated series in the Tokyo Dome. He'll do so having found success in his first taste of major league hitters outside of the World Baseball Classic.

"A couple things I noticed with big league hitters: They do hit mistakes, and they do take some splits that I threw," Sasaki said. "But I did feel really good about being able to jam some hitters. As long as I throw quality pitches, I should be able to get these guys out."