"To grab a goal" means to score a goal in sports, usually referring to football (soccer), by successfully getting the ball into the opponent's net. Full definition
The visitor were looking really eager to grab a goal in the first period as they created several dangerous goal scoring attempts which unfortunately were not converted by their players. (1000goals.com)
And it was the two strikers who grabbed the goals. (arsenalfcblog.com)
Almost grabbed a goal early in the second half. (theclockend.com)