The Fulham star is up to 12 goals on the season, leaving him one shy of his career best return of 13 last term, while Landon Donovan grabbed an assist for Everton.
The 28-year-old scored an emphatic hat trick against English third division side Charlton Athletic in a 4-0 FA Cup victory at Craven Cottage. Dempsey's performance increases his goal tally to 12, one shy of his career best total of 13 from last season.
The midfielder opened the scoring for his club in the 8th minute to give Fulham a 1-0 lead. The American doubled his tally in the 61st with a left-footed goal to match his earlier strike with the right.
Dempsey completed his first career hat trick in the 81st minute after Bryan Ruiz drew a penalty and the American stepped up and knocked it home to make it 3-0 for the Cottagers.
Damien Duff put any remaining doubts to bed when his deflected shot found the net in the 86th to give the match its final scoreline.
Fellow American Landon Donovan also helped his side to a win in the FA Cup. The Everton winger's corner was headed home by Johnny Heitinga to give the side a 1-0 lead four minutes in. Leighton Baines added a 78th minute penalty to give Everton a comfortable 2-0 victory over Tamworth.