For the competition, the late night host and the "Happy" crooner had to run down Hollywood Boulevard in 30 seconds snapping as many twofies as possible - selfies, but with a second person in them. In each photo, the other person's eyes and nose had to be in the shot in order for the snap to count as a point.
Jimmy's approach was to run down Hollywood Blvd. shouting "selfie" to get people's attention so he could snap a shot. Meanwhile, Pharrell had more of a laid back approach, posing in the middle of a crowd and walking around leisurely to get his photos.
In the end, Jimmy's frantic twofie snapping prevailed, with the host announcing who won when Pharrell appeared on his Jimmy Kimmel Live show earlier this week. Jimmy got 10 photos, while Pharrell only nabbed six.
The grand prize - Pharrell's hat.