The Open Championship isn't over. McIlroy and everyone else in contention have to believe they have a chance. But they're chasing a guy who's almost impossible to catch.

The world No. 1 leads the British Open by four shots and the SI Golf team debates whether the world No. 2 is the man to possibly run him down.

It was a return six years in the making, and it was a return that perfectly encapsulated Rory McIlroy. Making the trek back to Royal Portrush for The Open Championship -- now as a career grand slam winner -- the Northern Irishman experienced a topsy-turvy day as the hard stuff came easy and the easy stuff came hard.