PGA Championship

Valhalla Golf Club

The Loop

Is this the moment that will seal up Jason Day's first major win?

HAVEN, Wis. -- Birdies are flying again at Whistling Straits on Sunday. Perhaps the most impressive of the day so far? That's this 49-foot birdie bomb from leader Jason Day to get to 19-under.

How good was this?

That put Day up by three over Branden Grace. And now four up on Jordan Spieth.

Looks like 20-under is certainly in play. And this just might be one of the signature moments in the championship if Jason Day holds onto his lead.