PITTSFORD, N.Y. -- Jason Day and Scott Piercy started the day six shots off the lead.
Now both suddenly find themselves challenging more than just the course record.
Day and Piercy are both 6 under through their first 13 holes and within three of the lead.
On Friday, Jason Dufner, set a course record and became the 24th player to record a 63 in a major.
As for Day, he has birdied six of his last night holes after a bogey early in the round. Piercy, meanwhile, has five birdies in his last seven holes.
Only Jason Dufner and Henrik Stenson -- both at 8 under -- are ahead of them, along with leader Jim Furyk, who is another shot clear.
Day and Piercy are hardly the only ones to have gone low this week. Furyk and Adam Scott both opened with a 65, while Webb Simpson shot 64. But that was early in the week when the course was playing soft.
They are running out of holes, however, as they try to get in early, post a number and see what everyone else behind them does.