The two finalists met at the net to shake hands, Maria Sharapova standing a head taller, even with her shoulders slumped in disappointment.
She finished second again on Saturday.
Sharapova lost serve in the last game of each set and fell short in the latest bid for her first Sony Ericsson Open title, losing in the final to Agnieszka Radwanska 7-5, 6-4.
Sharapova, a three-time Grand Slam champion, is winless in four Key Biscayne finals. She was also the runner-up in 2005, 2006 and last year.
The pattern extends beyond South Florida. Ranked No. 2, she was runner-up at both the Australian Open and Indian Wells to Victoria Azarenka, which makes her 0-3 this year in finals.
"It's always tough, because you do a really good job to get there," Sharapova said. "It's obviously always the toughest round."
She hasn't won a tournament since August.
Radwanska, ranked a career-best No. 4, earned her ninth career title and fourth since last summer. She's 0-4 in 2012 against the top-ranked Azarenka and 26-0 against everyone else.
The match was 72 minutes old before Radwanska hit her first baseline winner. She was content to play the role of counterpuncher and extend rallies until the more aggressive, harder-hitting Sharapova would make a mistake.
There was a 28-stroke rally in the first game, but many of the points were quick, with Sharapova often too eager to end them. She finished with 45 unforced errors, most due to an unreliable backhand.
The relentless Radwanska committed only 10 unforced errors while chasing down almost everything, sometimes scooping balls at shoe-top level to keep a point going.
"She hit a lot of good balls on the run, and they were deep," Sharapova said. "She didn't just bring them back; she had something on them. Then the few errors on important points that I made, I thought maybe I shouldn't have gone for the line so much, and aimed a little bit closer to the middle."
Radwanska used pinpoint placement of her serves to compensate for their modest pace, and erased all three break points she faced.
"Today was a very tight match," she said. "I think I was just better for couple of points each set."
Radwanska gave credit for her style of play to her father and coach, Robert. He flew home before the match rather than exchanging his plane ticket so he could watch the final.
"He said, 'You're playing well. So you know what you have to do, and just text me after the game,'" she said with a smile.
Top-ranked Novak Djokovic will try for his third Key Biscayne title and second in a row when he plays 2009 champion Andy Murray in the men's final on Sunday.
The women's final took place on the hottest day of the tournament - a cloudless 85 degrees (30 C) - and the stadium stands were aflutter with fans fanning themselves.
Shouts from the South Florida spectators suggested a division in allegiances.
"Vamos Maria!" one spectator yelled for the Russian.
"Vamos Agnes!" another hollered for the Pole.
Sharapova draped a rolled-up cold towel around her neck during changeovers, but the heat didn't seem to faze either player. Instead it was the pressure to hold serve that made Sharapova wobble twice.
Serving at 5-6 in the first set, she committed four unforced errors - including a blown overhead - to lose the set.
The second set was just as close, and decided in similar fashion. Radwanska reached her only break opportunity of the set on the final point of the match. When Sharapova sailed a forehand long, Radwanska lifted her arms in triumph.
"Obviously I would have loved to be the winner," Sharapova said, "but that's just the way it goes."
Radwanska beat Venus Williams en route to the final and won every set she played. She improved to 2-7 against Sharapova, with her other victory at the 2007 U.S. Open.
"I'm playing against a really good player, second in the world right now," Radwanska said. "I had pretty much nothing to lose. It's just a great feeling to beat those kind of players, especially in the final playing great tennis."