Rafael Nadal worked to control an old foe while women's second seed Caroline Wozniacki overcame a bout of illness to advance Sunday at the Miami Masters, dpa reported.
With grey skies and humidity replacing sunshine, number four Nadal staged a fightback after losing a marathon first set, constructing a 6-7 (8-10), 6-2, 6-2 third-round win over Argentine David Nalbandian.
US Open finalist Wozniacki needed a doctor's mini-exam late in the first set and a locker-room pause after the second before carving out a victory over Russian Maria Kirilenko 1-6, 6-1, 6-4.
"I felt dizzy from the middle of the first set already," said the youngest player in the WTA top 10.
"Maria was playing a really good first set. I really didn't have too much of a chance. I just thought, okay, I mean, I don't have anything to lose. I just tried to go out there and fight for every point.
"Even though I didn't feel 100 per cent, I still went out there and fought. The third set I started to feel better. I think everything started to get to normal almost, and I felt much better."
Defending champion Victoria Azarenka, the fourth seed, took an easy win over Czech Lucie Safarova 6-4, 6-2.
Australian ninth seed Samantha Stosur completed another comeback from a set down to overhaul Virginie Razzano of France 4-6, 7-5, 6-1.
Russian 11th seed Vera Zvonareva beat Italy's Sara Errani 6-2, 6-3 while 14th-seeded US Open winner Kim Clijsters reached the fourth round easily against Shahar Peer 6-0, 6-1.
"Because she doesn't have a powerful game, I really didn't feel like I was threatened by her groundstrokes a lot," said the Belgian.
"I was dominating on a lot of the points and felt very comfortable just standing on top of my baseline and trying to make her move from side to side until I felt like I could take a couple steps in and go for the winner."
Seven-time Grand Slam winner Justine Henin beat Slovak Dominika Cibulkova 6-4, 6-4.
Nadal remains alive along with number one Roger Federer after early losses by second and third seeds Novak Djokovic and Briton Andy Murray.
Nalbandian, 28, is coming back from hip surgery last May and a January abdominal injury.
"I'm very happy how I'm doing in this American hard-court season," said Nadal, who had to quit the Australian Open with knee pain. "Every match right now I want to be really important for me, and every victory gives me confidence."
Nadal claimed the pair's last meeting a year ago at Indian Wells, with the winner saving five match points.
Nalbandian, ranked 161, earned the first set in 66 minutes on his third opportunity but was unable to stop the Nadal surge, which eventually paved the way to victory in two and a half hours.
The Spaniard finished with 21 winners and converted on five of six break points.
"When you go another time on court against a player with this talent, you are always a little bit scared. I started the match playing pretty well, really good," he said.
"Having a long first set for everything was better for me than for him. If I win the set it will be difficult for him to still believe in the victory. I felt he was a little bit more tired than me. He started to have more mistakes and was a little bit easier for me to play."
American hero and sixth seed Andy Roddick was untroubled by Sergiy Stakhovsky 6-2, 6-1, while Spain's Juan Carlos Ferrero put out John Isner of the US 6-2, 3-6, 6-3.
Spaniard Nicolas Almagro put out Jeremy Chardy of France 6-2, 6-7 (9-11), 6-3 and next faces Brazil's Tomaz Bellicci, a winner against Olivier Rochus - who upset Djokovic - 6-3, 6-4.