Earlier Williams claimed a rare win over big sister Venus booking her spot in the final with a ruthless 6-2 6-2 victory over the Wimbledon and U.S. Open champion.
The final will mark the second time in as many tournaments that Williams will play Capriati for a title having beaten the Australian Open champion in Scottsdale three weeks ago.
As she has done in much of the tournament, Capriati struggled early on to find her rhythm as fifth seed Seles, who became the youngest ever Miami Masters champion when she lifted the title as a 16-year-old in 1990, looked poised to make a return to the final after winning the first set.
But Capriati, playing in front of her hometown crowd, stormed back to take the second.
With the match approaching midnight, the two players appeared prepared to slug it out until dawn, matching shot for punishing shot from the baseline.
With neither Seles nor Capriati able to find the break, the third set went to a tiebreak, which the world number one took 7-4.
It will be the second consecutive time Capriati has appeared in the final here. Last year she squandered eight match points before falling to Venus Williams.
Capriati contests Saturday’s final holding a slight 4-3 edge in head-to-head meetings with eighth-seeded Serena, but has lost the last two.
The semifinal between Serena and Venus marked the eighth time the sport’s most famous siblings had met as professionals but only the second that Serena had walked away the winner.
Her victory also brought an end to a remarkable run of success on the Miami hard courts by defending champion Venus, who had been unbeaten at this event since a second round loss to Martina Hingis in 1997.
Venus came into the contest riding a 24 match win streak that included consecutive titles in 1998, 1999 and last year. She did not compete here in 2000 due to injury.
Serena’s victory also marked only the fifth time since 1971 and 28 head-to-head meetings between sisters that the younger sibling has come away the winner.
World number one Lleyton Hewitt battled his way to a 2-6 6-2 7-6 (7-4) win over Russia’s Marat Safin on Thursday to reach the semifinals of the Nasdaq-100 Open Masters and stretch his winning run in the U.S. to 22 matches.
Unbeaten on American soil since his U.S. Open victory last year and riding a two-tournament winning streak, the Australian’s run of success appeared in danger when sixth seed Safin took the opening set.
The set was only the third surrendered by Hewitt in his last 10 matches.
In the third set Hewitt was at his aggressive best, breaking Safin three times only to have the Australian Open runner-up break back each time.
After Safin had broken to level the set at 4-4, Hewitt immediately broke back, scampering to the net to fire a crosscourt winner.
Delighted by his effort, Hewitt screamed his approval, pumping his clenched fist and jumping in the air. But the celebrations proved premature.
With Hewitt serving for the match, Safin demonstrated some determination of his own, spectacularly diving across the court to send a return just over the net cord and get the break back.
Two more breaks and the set went to a tiebreak won by Hewitt 7-4.
RESULTS
WOMEN:
Semifinals: 1-Jennifer Capriati (U.S.) beat Monica Seles (U.S.) 4-6 6-3 7-6 (7-4); 8-Serena Williams (U.S.) beat 2-Venus Williams (U.S.) 6-2 6-2
MEN
Quarterfinals: 1-Lleyton Hewitt (Australia) beat 6-Marat Safin (Russia) 2-6 6-2 7-6 (7-4); 12-Roger Federer (Switzerland) beat 26-Andrei Pavel (Romania) 6-1 6-1.—Reuters