Jackson Kowar's pitching prowess was on full display even as he finished the longest start of his professional career.
The Royals' No. 5 prospect gave up four hits and struck out six over eight innings as Northwest Arkansas blanked Tulsa, 8-0, on Saturday night at ONEOK Field.
Video: Naturals' Kowar notches sixth strikeout with heater
"That was definitely good to reach that milestone," Kowar said after pitching into the eighth for the first time.
Admitting it was one of those days where he had to fight some early struggles, Kowar faced his greatest threat in the first inning. Drew Avans led off with a single and stole second base. After rehabbing Major Leaguer Jedd Gyorko lined back to the right-hander, Avans advanced to third.
"Gyorko smoked one right at me," Kowar said. "Luckily, I got enough glove on it that I knocked it down and threw him out."
With the infield in, Dodgers No. 24 prospect Cristian Santana followed with a grounder to second baseman and Royals No. 30 prospect Gabriel Cancel, who threw out Avans at the plate.
"The defense definitely picked me up," Kowar said. "I was fortunate that they hit some balls pretty hard at some guys early in the game."
After Avans' single, Kowar retired nine straight before Gyorko led off the fourth with a single. The 22-year-old also allowed leadoff singles in the fifth and sixth, but that's all he gave up until Carlos Rincon reached on a throwing error by shortstop Taylor Featherston with two outs in the eighth.
In addition to crediting catcher Nate Esposito with calling a strong and settling game, Kowar was happy with how he had all three pitches -- fastball, changeup and curveball -- working. The breaking ball has allowed the highly touted prospect to improve in his first full pro season.
"It's a pitch I didn't throw a ton in college," the University of Florida product said. "I threw it, but I'm trying to bring it more, especially when I'm turning the lineup over. Having three pitches and three different looks has definitely been big for me."
With Errol Robinson at the plate and two outs, Kowar snapped off two curveballs for strikes before throwing a 94 mph fastball for his sixth strikeout.
Gameday box score
"Being able to go eight up and down and still have my stuff out there was encouraging, for sure," he said.
2019 MiLB include
The 2018 first-round pick had gone seven innings four times this season. He threw 102 pitches, 67 for strikes, and lowered his ERA to 3.02 in eight Texas League starts. Kowar was promoted from Class A Advanced Wilmington on June 22 after going 5-3 with a 3.53 ERA in 13 starts.
The former Gator spent his first professional season with Class A Lexington, where he was 0-1 with a 3.42 ERA and held opponents to a .200 average in nine starts.
Anderson Miller hit a three-run homer in the Naturals' five-run fifth, while Royals No. 4 prospect Khalil Lee and 18th-ranked Kevin Merrell each chipped in a pair of RBIs.