TAMPA, Fla. (AP) -- Diego Serna scored three goals and added an assist as the Miami Fusion beat the Tampa Bay Mutiny 4-1 on Wednesday night in Major League Soccer.

Serna opened the scoring 45 seconds into the game -- the fastest goal from the start of a game in Miami history and the quickest allowed by Tampa Bay.

Serna made it 2-0 in the 19th minute and added his seventh goal of the season in second-half injury time.

Welton, who set up Serna's first two goals, gave the Fusion a 3-0 lead in the 56th minute.

Mutiny star Mamadou Diallo scored his league-leading 13th goal in the 64th minute.

Fusion goalkeeper Nick Rimando made a diving save on Carlos Valderrama's penalty-kick in the 62nd minute. The Mutiny have converted just two of six penalty kicks this season.

Miami snapped a three-game road losing streak to improve to 6-7-4, while Tampa Bay dropped to 8-8-0.

The two will meet again Saturday night in Fort Lauderdale.