OAKLAND -- Sean Manaea arrived on the scene Friday -- with hair that hasn't been cut in nearly a year barely contained by an A's cap -- along with an even greater volume of poise that served the big lefty well in his big league debut.
Manaea's final line was nothing extraordinary; in fact, it looks mediocre at best on paper, with four runs, four hits and four walks allowed in five-plus innings. But that hardly told the whole story, for the 24-year-old Manaea, considered the club's top pitching prospect, greatly impressed in Oakland's 7-4, walk-off victory over Houston.
"He was excited," catcher Stephen Vogt said. "He was antsy, probably a little nervous. I don't think many people saw it, but right when he took the mound for his warmup pitches, he kind of looked around and took a deep breath. I thought that was really cool to notice that and just make you love the moment."
• A's Top 30 Prospects
From there, Manaea let loose, facing the minimum during his first inning of work despite offering up a one-out single to George Springer, who was promptly caught stealing. Young phenom Carlos Correa swung through a 3-2 slider from Manaea to end the frame.

That Manaea was able to induce outs with that pitch was telling; it was the one the A's instructed him to fine-tune when he was directed to Triple-A Nashville following an extended stay in big-league camp -- his first with an Oakland club that reeled him in last summer in the Ben Zobrist trade with the Royals, who drafted Manaea with their second first-round pick in 2013.
The slider wasn't quite consistent all night. None of his pitches were, and he admitted to being too fine with many of them, but Manaea threw plenty of good ones -- particularly with his lively fastball -- to remind the A's of their fortune to strike such a deal.

The southpaw surrendered a leadoff homer to Evan Gattis to begin the second, but he wouldn't find trouble again until the sixth, when he was touched for three runs -- two with Sean Doolittle on the mound.
"I think I got past the point where I was really, really nervous and anxious and just kind of felt numb for a little bit," Manaea said. "Just going out to the mound for the first inning and looking around and seeing all the fans, it was amazing. I was really, really excited. I was just trying to keep all those emotions in check and keep as calm as possible and it was kind of hard at times, but I tried my best."
More than 20 friends and family members, most of them from Manaea's home state of Indiana, were in attendance at the Coliseum, where all were treated to a walk-off ending.
"Unreal experience," Manaea said. "I'm so happy to be here."
"I thought he was good," A's manager Bob Melvin said. "It's not an easy lineup for a lefty to have to go through."