BOSTON — Young baserunners at home, make sure you at least look at your third-base coach.

Adherence to that simple rule would have spared the Sox’ Coco Crisp some embarrassment and might have led to a run or two last night in the sixth inning.

Crisp was running at second base with two outs and Boston on top, 4-1, when Jacoby Ellsbury hit a weak roller to the shortstop hole. Tampa Bay shortstop Jason Bartlett fielded the ball but knew he had no chance at throwing out the speedy Ellsbury at first, so he held the ball and looked toward third, hoping to catch Crisp rounding the bag too far.

Crisp, his head down, zipped around third, almost running over third-base coach DeMarlo Hale, who had his right hand up in the “stop sign” signal even before Crisp reached the base.

But Crisp had his mind made up that he was going home, either because he thought the ball would go through or because he thought if the throw went to first base and Ellsbury beat it, he’d be able to score.

When he finally realized Hale was yelling at him to stop, Crisp was too far past the bag to get back. As Bartlett tossed the ball to third baseman Evan Longoria, Crisp basically gave up. Eventually, he was put out in a rundown.

skrasner@projo.com