He was holding a filled popcorn bucket in one hand and a beverage in the other. So he did what any true baseball fan would do.
He held his popcorn bucket up high and snagged the foul ball with one hand. His buddy immediately jumped into his arms in celebration.
Most of the popcorn exploded out of the bucket, but at least he got the souvenir. Side note: His beverage was still intact.
Well done, young man.