Morales hit a two-run homer with two outs in the ninth inning to lift the Mariners to a 6-4 victory over the Kansas City Royals on Wednesday night.
The Royals used eight pitchers, tying a club record for a nine-inning game.
Walker, who became the youngest Mariners starting pitcher (21 years, 17 days) to pick up a victory in his major league debut on Friday at Houston, struck out two in the first inning, his fastball touching 97 mph.
The 6-foot-5 Walker, who was a basketball star in high school with a 21-point average, did not allow a hit over the first three innings, but yielded four runs, four hits, a walk and a sacrifice fly in the fourth to tie the score.
Manager Eric Wedge opted to send Walker out for the fifth and he responded with a 1-2-3 inning.
"In the fourth, he just came up in the zone a little bit," Wedge said. "I was glad to see him get through it. And then I was really happy to see him out there in the fifth and pitch another inning for us. I felt it was important to go out in the fifth. That proves something to him. We know he can do it.
"I love his repertoire of pitches and the way he works, his cutter and his breaking ball off his fastball. The changeup will continue to come, too."
Walker was glad to get a chance to return for another inning.
"I thought the fifth inning was real big for me," Walker said. "I wanted to have a clean inning and keep my team in the game. I was a little shocked I was going back out because they are monitoring my innings and it was a close game. I'm glad he sent me back out and I'm glad to go out and have a clean inning."
Walker threw 79 pitches.
"You can see what all the hype was about," Royals manager Ned Yost said. "He's got a free and easy power arm. He's a good talent."
"You've got different options there," Yost said of Morales' homer. "You can go down and away, bust him inside or go back foot. You just don't want to go there. But it wasn't Morales as much as Gutierrez. That's the guy you want to go for there so you don't get to Morales."
Crow had Gutierrez down in the count 1-2 before walking him.
"I've got to put him away there and Morales doesn't get up," Crow said. "I just left it up to Morales and it hurts more so because the home run lost us the ballgame."
Jarrod Dyson's two-out, two-run single made it 4-4 in the fourth, but that was it for the Kansas City offense. Salvador Perez's sacrifice fly scored Eric Hosmer, who had singled for the first Kansas City hit. Billy Butler singled home Emilo Bonifacio, who led off the inning with a walk, for the first run.
The Mariners, who had scored just four runs in losing their previous three games, scored four runs in the first four innings and chased Royals right-hander Ervin Santana.
Santana failed to make it through the fourth, charged with four runs, seven hits and three walks in 3 1/3 innings, his briefest outing of the year.
OF Lorenzo Cain, who missed 25 games with a pulled oblique, was activated Wednesday, but was not in the Royals lineup. "I've still got to get the timing back," Cain said. "That might be a little tough." Cain will be restricted to a late-inning defensive replacement and pinch-runner for a while. .. Royals 2B Chris Getz, who left after two innings Tuesday with dizziness and an upset stomach, did not play Wednesday as the club was waiting on concussion tests results. ... Mariners RHP Felix Hernandez, who left in the seventh inning Monday with lower back cramps, is still listed as the probable starter Sunday. "He is doing better, so, that's good," Wedge said. "Let's see how he is tomorrow. I'm encouraged that he's feeling better today." ... LHP Joe Saunders, who starts Thursday, is 4-0 with a 2.81 ERA in eight career starts against the Royals. RHP Jeremy Guthrie, who is 9-4 this season at Kauffman Stadium, will start for Kansas City.