Indians leading the Red Sox by two runs in the fifth. Hanley Ramirez sends a drive to center. Tribe fly-catcher Austin Jackson gives chase.

And then ... 

We share Mr. Ramirez's sense of baseball amazement. That, people, was a catch.

Some pretty still photography ... 

The Red Sox actually challenged the catch, but it stood upon review. Here, however, is the relevant portion of Rule 5.09 ... 

A fielder, in order to make a catch on a foul ball nearing a dugout or other out-of-play area (such as the stands), must have one or both feet on or over the playing surface (including the lip of the dugout) and neither foot on the ground inside the dugout or in any other out-of-play area.

Jackson had both feet over the playing surface so it was indeed a catch. Actually, it was so much more than "just" a catch. Jackson's been thumping the ball in limited duty for the Tribe this season, and now he's made one of the best plays of 2017.