The 17-year-old right-hander took a one-hit shutout into the ninth inning as the AquaSox held on for a 4-2 victory over the Eugene Emeralds.
Making his fifth start since signing with the Mariners last summer, Sanchez (3-0) ended up allowing two runs on two hits and two walks while striking out five over eight-plus frames.
AquaSox manager Rob Mummau and pitching coach Rich Dorman agreed the youngster had earned a shot at a complete game after limiting the Emeralds to a single over eight innings. Sanchez threw 93 pitches before giving way to Grady Woods.
"The way he pitched tonight was above and beyond what a 17-year-old is capable of," said Dorman, who pitched in the Minor Leagues for nine years with the Rays, Mariners and Marlins organizations. "We were very confident with him going into the ninth. That's why we gave him the ball."
Sanchez (3-0) was considered one of the top Venezuelan pitching prospects and one of the best prospects in all of Latin America when the Mariners signed him to a deal that included a reported $2.5 million bonus.
Even at his young age, he's been able to produce in the Northwest League. In his debut on June 15, he allowed one run on two hits and two walks while striking out four over six innings in a win over Tri-City.
Dorman was effusive in his praise of the 6-foot-1, 205-pound teenager. He said Sanchez had both the emotional and physical maturity to be face 21- and 22-year-olds.
"I almost forget he's 17 watching him pitch," said Dorman, "that's how impressive he looks. It looks normal, it looks natural with what he's doing -- his ability to repeat his delivery as well as he does and to compete as well as he does. And the thing that makes him so good is he controls his emotions so well, pitches within himself."
In five starts with Everett, Sanchez has compiled a 2.76 ERA over 32 2/3 innings, striking out 25 batters and walking 11. Perhaps more impressively, he's showed impressive durability, logging at least six innings in each outing.
"He pitched against this club back-to-back starts, they just saw him. And he made his adjustments the second time through," Dorman noted. "He was better. The kid's a competitor, he's fierce. Before the game, he said, 'We're winning today.' You don't hear that from a 17-year-old kid.
"I just looked him in the eye and I believed him."
With Sanchez off to such a stellar start at such a young age, it's easy to envision a rapid ascent. According to Dorman, he has the potential to be a front-line starter in the big leagues.
"He's got a big upside. With his age and where he's going, he can hopefully be a front-end starter for our Major League team," Dorman said. "Whether that's going to happen is up to him and, obviously, everybody involved with keeping him on the right track.
"He'll continue to work hard and good things are going to happen for him. He's very respectful, he listens. He's a joy to coach, I'll tell you that much."
Sanchez exited after allowing a single to Ronnie Richardson and walking Corey Adamson. Wood gave up a single to Dane Phillips that loaded the bases, then walked Alexi Colon to force in a run. After Jeremy Baltz struck out, Alberth Martinez grounded out to plate Adamson, but Wood retired River Stevens on a bouncer to third to nail down his second save.