MLB's Ke'Bryan Hayes Commits Epic Blunder During Home Run, You Forgot To Touch 1st!

One of the best young hitters in the MLB looked more like a Little Leaguer on Tuesday ... 'cause Ke'Bryan Hayes forgot to touch 1st base on a home run -- and the gaffe REALLY cost his team.

The Bad News Bears moment all went down in the bottom of the 1st inning of the Pirates' game against the Dodgers ... when Hayes cracked a shot to the opposite field.

The ball was a bullet that hit the foul pole, giving Hayes a home run ... but there was just one problem -- he never tapped 1st on his way around the diamond!

The Dodgers noticed Hayes' critical error, challenged the play ... and sure enough, Hayes was ruled OUT for the mistake.

Of course, the play was HUGE ... the first 4 innings ended up being played to a 0-0 tie, with the Dodgers only ultimately winning 5-3.

After the game, Hayes' manager said his 24-year-old third baseman needed to be better.

"Obviously, Ke' got caught watching the ball,'' Pittsburgh manager Derek Shelton said, before adding, "If he even thinks he misses [the bag], he has to go back and touch it."

Don't worry, Pittsburgh should find it easy to forgive Hayes ... he's batting .333 so far this year, and he's got future star written all over him.