The tournament teed off Thursday morning in Scottsdale.
Many of the best golfers in the world are playing at the TPC Scottsdale, including Tiger Woods and Phil Mickelson.
They're all hoping to win at the PGA tour stop that's been dubbed the greatest show on grass.
Before the tournament started, there was a lot of fun on the links between pros and celebrities at the Annexus Pro-Am.
75,380 people came out to watch the event.
All eyes were on Tiger Woods. He's playing in his first PGA event since August and his first Phoenix Open since 2001.
He looked pretty relaxed, but his Pro-Am group took 17th place.
Not only do they have golf, but they also have one of the valley's biggest parties.
The Bird's Nest opened on Wednesday night with Capital Cities.
Darius Rucker will be the main act on Thursday night.
Tiger Woods is scheduled to tee off at 12:07 p.m. on the first hole.
Valley favorite, and ASU alum, Phil Mickelson will tee off at 7:57 a.m. on the 10th hole.