WASHINGTON -- Justin Steele came striding off the mound, hunching over as he let out a celebratory scream. The Cubs pitcher had just put the period on another strong start -- firing an elevated heater by the bat of Washington's Lane Thomas.

Before Tuesday night's game at Nationals Park devolved into a battle of the bullpens, Steele provided a quality start to open an eventual 7-5 win for the Cubs in 11 innings. It was another statement from an arm that has very much become part of the 2023 rotation plans.

"He has what it takes to be one of those elite starters at some point," Cubs catcher Willson Conteras said. "With gaining more experience, pitching more, staying healthy, I think he's going to be one of those elite pitchers."

That is quite a compliment coming from Contreras, who took over as Jon Lester's primary catcher after now-manager David Ross' playing days were over. Contreras has also been the main batterymate of Kyle Hendricks, and he has caught a long list of decorated arms.

In that final plate appearance of Steele's outing, he had cycled through seven pitches (four sliders) against Thomas before his last pitch. Contreras said the left-hander shook off signs until the catcher called for the four-seamer.

"He trusted it," Contreras said. "He shook to it and I was like, 'OK, that's fine.' I'm a guy that I think if you're going to get beat, you've got to get beat with your best stuff."

"He just kind of let one eat," Ross said. "I thought that was the difference in the final at-bat. Just really getting after it."

Contreras said he told Steele that this was "the best night I've ever seen him pitch in my life." The catcher raved about the lefty's growth this year through a willingness to listen to advice and ask the right questions. He said Steele is on his way to becoming a "complete pitcher" for the Cubs.

The recent results certainly support that kind of assessment.

Back on May 26, Steele yielded seven runs and lasted just two innings in a road outing against the Reds, causing his season ERA to balloon to 5.40 through nine turns. In 13 starts since that point, the lefty has pieced together a 2.48 ERA for the North Siders.

Against Washington, Steele logged six innings, allowing one unearned run -- courtesy of his own throwing error on a pickoff play in his last frame -- with five strikeouts. That gave him a 1.67 ERA with 50 strikeouts in 43 innings in his last eight starts, giving him a 3.43 ERA overall this season.

"I felt like I was kind of in control of all my pitches," Steele said. "I was commanding all of them, putting them where I wanted to when I wanted to. As far as all my starts this year, and commanding all my pitches, it was one of my better starts."

Steele led with his four-seamer (47 percent) and slider (41 percent), and he mixed in a handful of sinkers, per usual. There was a new wrinkle against the Nationals, though. The lefty has been working on a changeup since the spring, and he featured it a season-high seven times in the game.

Washington's Joey Meneses saw four of those offspeed pitches, swinging and missing once and connecting for a single on another. More notably, Steele induced a double-play off the bat of Thomas in the second inning with his improved changeup.

"That's huge as far as building confidence with the pitch," Steele said. "I think moving forward it'll be a big pitch."

It was another step forward for a pitcher who is growing into a trusted part of the rotation not only for this year, but as the Cubs map out their plans for the next few seasons.

"I feel like I say this every one of his starts," Ross said. "He just keeps getting better, right? There's learning moments -- things he's worked through. We talked through one inning that he threw up a zero, but I think there was some growth in there that we talked about and some areas that he can continue to improve on.

"I think it's just important that he makes his starts, has adversity, has different areas to try his repertoire and continue to just succeed in the year he's established himself as having. Just continue to build on that. The stuff, I thought, was really electric tonight."