Roki Sasaki took a significant step forward in his development Thursday night, showing both flashes of dominance and areas for improvement during the Los Angeles Dodgers' 6-2 win over the Seattle Mariners.

Over the first five innings at Dodger Stadium, Sasaki was largely flawless, showcasing 100 mph fastballs and a potent splitter that generated swings and misses. He struck out seven batters and allowed only two singles and a walk during this stretch. "This start, for five innings, was even better [than his previous ones]," manager Dave Roberts said of the pitcher's performance.

However, Sasaki faltered in the top of the sixth inning, allowing two runs before being replaced by reliever Jack Dreyer. The troubles began with a triple from Cole Young, followed by an RBI double from Randy Arozarena. Sasaki then issued a walk and gave up a single, loading the bases before Cal Raleigh drew a run-scoring walk, prompting his exit.

"Of course there were parts that weren’t good, and that I have to reflect upon," Sasaki said through an interpreter. "But I was good through the fifth. And I want to keep that image in my head." Dreyer entered the game with the bases loaded and one out, successfully preventing any further runs from scoring and preserving Sasaki's final line.

Despite the late stumble, Sasaki lowered his earned run average to 4.64 on the season. He has allowed just three earned runs in 18 innings across three starts in the second half of the season, a marked improvement from his performance prior to the All-Star break. "I think he just kind of decided that it’s time to go and finish strong," Roberts commented. "It’s a new half and it’s a new beginning. You’ve seen a different player, to be quite honest. There’s a lot more confidence." The Dodgers continue to evaluate Sasaki's progress as they assess their pitching staff for potential postseason roles. Thursday's outing provided further signs of his recent surge and why he might be a contributor down the stretch.