The seventh seeded pair of Roger Federer of Switzerland and Max Mirnyi of Belarus ended the winning run of sixth seeds Leander Paes of India and his Czech partner David Rikl at the Nasdaq-100 Open ATP Tennis Masters Series.
Federer and Mirnyi won the final 7-5, 6-3.
Meanwhile, Serena Williams extended her 2003 unbeaten streak by beating American countrywoman Jennifer Capriati for the seventh consecutive time 4-6, 6-4, 6-1, to win the women's crown.
Williams, who is ranked No. 1 and 17-0 this year, also beat Capriati in the 2002 final.
No. 2-seeded Andre Agassi advanced to the men's final by beating No. 9 Albert Costa of Spain 6-2, 6-4.
Agassi, bidding for his sixth Key Biscayne title and his third in a row, won a 17-minute first game and led Costa the rest of the way. Agassi finished with 29 winners and just 18 unforced errors in the one-hour, 42-minute match.
His opponent in the final will be No. 5 Carlos Moya of Spain, who advanced by beating Paradorn Srichaphan of Thailand 6-4, 6-2 on Friday night.