Ken GriffeyJr.'s 400th homer became a special present on his father's 50th birthday.

Griffey became the youngest major leaguer to reach that milestone when he connected Monday in the fourth inning of Cincinnati's game against Colorado at Coors Field.

Griffey sent a 2-0 pitch from Rolando Arrojo into the left-field seats, a 378-foot blow. It was his second homer of the season and second in as many days.

He was cheered by the crowd as he rounded the bases, then was high-fived by teammates and hugged by his father, Reds coach Ken Griffey, in the dugout.

At 30 years, 141 days, Griffey beat the previous mark, set by Jimmie Foxx, who was 30 years, 248 days old.

Griffey is fifth on the career homer list among active players, trailing Mark McGwire(525), Barry Bonds(447), Jose Canseco(431) and Cal Ripken Jr.(403).

Griffey's historic homer came on his father's 50th birthday. It was the fourth time he has homered on his father's birthday, including homer No. 1 in 1989.

``I haven't really had a chance to think about it,'' Griffey said of No. 400. ``The biggest thing is, I tell my dad it's a cheap way of not buying him a gift on his birthday. So he'll get this ball. My mom got 399, and he's got 400.

``But it's on his birthday, so it's a special moment for both of us, especially that I can do it in front of him. I don't think I started smiling until I got to the dugout and looked at all the guys sitting there waiting for me to come in. That was pretty special.''

Asked where his 400th homer puts him in baseball history, Griffey said, ``I don't know. Over my last 12 years of playing baseball, I think the No. 1 thing is that I played with my father. I got to call him a teammate. He got to take me out to lunch and things like that.''

Reflecting on his career, Griffey said, ``I started when I was 19, which is not normal in this time and age. And I've stayed pretty healthy and somewhat consistent over the years and that helps. But I don't really think about the numbers. I just think about helping the ballclub. If I hit a home run, I hit a home run.

``The only numbers I really want to see are the ones in the win column.''

During lengthy post-game interviews, Ken Griffey yelled to his son, ``Hurry up, I don't want you to be late for my birthday.''

Griffey's homer was caught by Rockies season ticket holder Jay Wissot, who attended the game with his wife, Alyn Park, of Denver. They requested an autographed hat, glove and warmup top, all of which they promised to donate to charity. They also requested a $1,000 donation in the name of Griffey's mother, Birdie, to the Conflict Center of Denver.

``This is like the fourth glove I've lost this year,'' Griffey said. ``I'll have to call tonight and have a glove sent in. It was my game glove.''