The 43-year-old actor donned a dapper suit with a cleanly-shaven goatee and joined co-stars Bradley Cooper, Heather Graham, Ed Helms, Justin Bartha, Ken Jeong and director Todd Phillips for the star-studded event.
In addition to his beardless image, Zach recently told Conan O’Brien that he recently “stopped drinking” after "getting into much trouble" with alcohol.
As for the comedic trilogy coming to a close, the hilarious actor told Us Weekly, “I’m not sad. I’m really excited about being able to celebrate this with the fans across the country."
