Ken Griffey Jr. is hitting .179 this spring with one home run. (Lenny Ignelzi/AP)

PEORIA, Ariz. -- The first walk-off grand slam in Ken Griffey Jr.'s Hall of Fame career didn't really count, because it came in a Spring Training game.

But it sure brought a big smile to his face on Friday.

Griffey's first home run as a 40-year-old came with one out and the bases loaded in the bottom of the ninth inning.

After getting the green light on a 3-and-0 count and swinging over two consecutive pitches out of the strike zone, Junior sent a full-count fastball from Kip Wells over the fence in right-center, giving Seattle a 6-5 Cactus League win.

The first thing he saw when he went around third base was a large crowd waiting for him 90 feet away.

"My guys were at home plate," the Mariners' designated hitter said. "That's one of the best feelings in baseball, to see your guys at home plate waiting for you."

The Major League's active home run leader with 630, Griffey said afterward that he never had ended a game at any level with a grand slam.

"It was just one of those things," said Griffey. "I was just happy to get the ball up in the wind tunnel."

It was a windy afternoon at Peoria Stadium, and the hit that ended the game was aided by the wind. But if it hadn't gone out, it might have scored three runs anyway.

But the ball snuck over the high fence, out of the reach of Reds right fielder Wladimir Balentien.

"Pretty crafty," said Mariners manager Don Wakamatsu of Griffey's at-bat. "He set [Wells] up with two balls in the dirt, and hit the home run."

Who would have thought?

Well, Minor League hitting coach Alonzo Powell for one.

"'Zo' called it," Griffey said. "He told me before the inning started, 'The bases will be drunk and you are going to hit a walk-off.'"

Yeah, right.

Griffey had been 0-for-4 in the game and was hit in the foot by a pitch. His batting average had fallen to the upper .130s and he was lunging at way too many pitches.

"I have just started to be able to some things, like being able to sit back and look at pitches," Griffey said. "I get caught a lot of times being out in front, and that's from being anxious."

The process of getting ready for the regular season takes longer for someone his age, but he says he's getting there.

So does Wakamatsu.

"He's been hitting the ball pretty hard," Wakamatsu said. "He lined out to first base [on Friday] and in his last game he hit the ball well. He's getting in shape like everybody else. But I think it was good for him."