Colon has a long history of success against Seattle and is now 13-1 with a 2.12 ERA in 15 starts at Safeco Field. The 17-year Major Leaguer improved to 9-8 on the season with a 4.03 ERA and is third among active pitchers with 198 career wins, trailing only the Giants' Tim Hudson (213) and Yankees' CC Sabathia (208).
"This guy knows how to pitch," said Mariners manager Lloyd McClendon. "Check the resume -- he's pretty good."
At the other end of the age spectrum, the 21-year-old Walker allowed just two runs and two hits in his five-plus innings, but issued six walks and a hit a batter before being lifted after loading the bases with no outs in the sixth.
Reliever Dominic Leone worked out of that jam by allowing just one run to score on a sacrifice fly, leaving Walker with two runs allowed in his third start with Seattle this season. Walker saw his record fall to 1-2 with a 3.60 ERA.
"I know it was a loss, but it was a step in the right direction," said Walker, who was optioned back to Triple-A Tacoma after the game as the Mariners won't need a fifth starter again until Aug. 2 due to an upcoming off-day Monday. "It's something to build off of, a lot more positive than negatives, definitely."
McClendon said it's important to remember that Walker, the No. 5 ranked prospect in baseball by MLB.com, is just getting his feet wet in the Major Leagues.
"He's OK," McClendon said. "His command of the fastball, we talked to him about it. His command of the fastball's got to get better, and he will get better. One thing we have to remember is this man is 21 years old. Most kids 21 are still in college. He's doing pretty good. He's going to be a pretty good pitcher at this level and I know he's committed to working hard at it."
Walker struggled with fastball command in his prior start with Seattle when he walked five in a four-inning outing against the White Sox on July 6, and he looked erratic again in the first inning when he walked two and gave up a run on a double by Daniel Murphy.
But the youngster seemed to pitch with purpose -- and a more aggressive attitude -- following that frame, and he zipped through the next three innings before hitting Mets shortstop Ruben Tejada in the helmet with a 94-mph fastball with two outs in the fifth.
Tejada was forced to leave the game, and Walker followed with a four-pitch walk to Eric Young Jr. before getting out of the inning with a groundout by Murphy. But he allowed a leadoff single in the sixth and walked two batters before McClendon called it a day after 94 pitches.
Walker acknowledged that beaning Tejada shook him a bit.
"Definitely," Walker said. "I've never hit anybody in the head with a fastball, so it was definitely scary. But I heard he was OK, thank goodness. … You have to kind of shake it off and get back into the game, but it is tough."
The Mets added a run in the seventh off Leone on an RBI single by David Wright for a 3-0 lead before the Mariners rallied in the eighth with an RBI double by Brad Miller and a run-scoring groundout by pinch-hitter Willie Bloomquist.
That rally lost steam after Bloomquist -- who initially was ruled safe -- wound up out on a replay review and Endy Chavez struck out to strand Miller at third. Seattle threatened closer Jenrry Mejia in the ninth when Cano and Corey Hart singled, but Logan Morrison struck out to end the game.
Cano acknowledged it was Colon's day, but said the Mariners will put this one in the rearview mirror quickly.
"The last thing we can do is hang our head and start worrying," said Cano, who went 2-for-4 to put his average at .332. "We just have to turn the page and move on. We can't think about a game we lost. Whatever happened, turn the page and be ready for tomorrow and a new series."
Seattle still holds the second Wild Card spot in the American League standings, but the Mariners fell to 53-48 with their second straight loss to the Mets and are now 2-4 since the All-Star break heading into a four-game series with the Orioles. The Mets have won 11 of their last 16 games to improve to 48-53.