Andy Roddick beat Roger Federer for only the third time in their 24 meetings on Monday, dominating with his serve to win 7-6 (4), 1-6, 6-4 in the third round at the Sony Ericsson Open.
Roddick broke serve only once but held every service game in the first and last sets. After falling behind 15-30 in the final game, he closed out the victory with an ace and two service winners, all at more than 130 mph.
On paper, it looked like a mismatch between former No. 1s, each a two-time champion in the event. The third-ranked Federer began the night 40-2 since the U.S. Open, while Roddick was ranked 34th, the lowest he has been since 2001.
Roddick ended Federer's streak of 77 consecutive wins against players outside the top 20.
Serena Williams matched a career high with 20 aces and whacking enough thunderous groundstrokes to beat Samantha Stosur 7-5, 6-3 and advance to the quarterfinals.
"My serve was hot," Williams said. "I was like, 'That's pretty cool.'"
She avenged a loss to Stosur when they last met in the U.S. Open final in September.
"That wasn't in my mind," Williams said. "I just thought, 'This is a new game.'"
Top-ranked Victoria Azarenka lost 10 of the first 11 games, then rallied to remain unbeaten this year by beating No. 16-seeded Dominika Cibulkova 1-6, 7-6 (7), 7-5. Azarenka was two points from defeat five times, but swept the last three games and extended her winning streak to 26 matches, all in 2012.
Also reaching the quarterfinals was No. 2 Maria Sharapova, who overcame 11 double-faults to beat Ekaterina Makarova 6-4, 7-6 (3). Sharapova won despite committing 52 unforced errors and losing her serve four times.
No. 1 Novak Djokovic advanced to the fourth round by beating No. 27-seeded Viktor Troicki 6-3, 6-4. Djokovic is bidding for his third Key Biscayne title and second in a row.
No. 8-seeded Mardy Fish assured he'll remain the top-ranked American man by beating No. 28 Kevin Anderson 6-4, 6-3. Fish has yet to play in the stadium this tournament and instead faced Anderson at 11 a.m. on the grandstand court, but he said that was fine because prefers an early start.
"I like to know my fate," Fish said. "I like playing in the heat. And I think everyone likes to know exactly when they play."
Federer lost only seven points on his serve in the opening set, but when he failed to put away an overhead trailing 4-3 in the tiebreaker, the match swung Roddick's way.
Federer squandered another chance with a 1-0 lead in the third set, failing to convert four break points in the next game. After Roddick escaped for 1-all, he earned his lone break in the next game, his grunts filling the stadium as he cracked four forehand winners.
Roddick served out the final four games without facing a break point. When he let loose a 134-mph serve to win the final point, he raised his arms and waved his racket at the heavens.
Roddick had cause to give thanks: He had lost 52 of 64 sets against Federer entering the match. Federer had won six meetings in a row since Roddick beat him in the Key Biscayne quarterfinals in 2008.
The No. 10-seeded Williams lost only six points on her first serve against the No. 6-seeded Stosur, but had to rally after being broken in the first game of each set.
Williams failed to convert her first seven break-point chances, then muscled her way back into the match. She also showed finesse, such as when she chipped a forehand drop shot that barely cleared the net for a dainty winner.
Is a shot like that fun?
"It was more nervous than fun," Williams said. "I was like, 'OK, is it going to go over?' Then it was, 'Now, oh, is she going to get it?' So it was more like that as opposed to fun."
Williams' best stroke was her serve. She hit six aces during a 20-point game to hold for 3-2 in the second set. After falling behind love-40 in the final game, she smacked three aces and eventually reached match point.
Her final serve spun so violently it kicked head-high to handcuff Stosur, who could only push the ball wide. A jubilant Williams hopped, skipped and pumped her fists.
Williams is playing in her first tournament since January after being sidelined by a left ankle injury. She hasn't won a title since August, and seeks a record sixth Key Biscayne championship.
"I'm really trying so hard," she told the crowd. "My mom gave me the ultimate pep talk last night, so thanks, Mom."