World number two Rafael Nadal launched his bid for a third successive Rome Masters title with a below-par 6-4, 6-2 win over Italian wild card Daniele Bracciali on Wednesday.
The 20-year-old Spaniard, who extended his claycourt winning streak to 73 matches after receiving a bye into the second round, was joined in the last 16 by third seed Andy Roddick and fourth seed Nikolay Davydenko.
Roddick beat former French Open champion Gaston Gaudio 6-1, 7-6, while Davydenko defeated compatriot Marat Safin 7-6, 7-5.
Fifth seed Novak Djokovic completed a clean sweep of victories for the top five players, holding his nerve to edge out Robin Soderling 3-6, 6-4, 6-3.
World number one Roger Federer reached the last 16 on Tuesday with a win over Nicolas Almagro.
Nadal, who is aiming to equal Thomas Muster's professional era record of three wins at the claycourt tournament, struggled to find his rhythm in the early stages of the match with Bracciali -- though he later put his slow start into context.
"I felt a bit dizzy and it was difficult for the first eight games but after that it was fine," Nadal told reporters.
Asked whether he was sick, Nadal replied: "I don't know. I felt a bit dizzy also before the match, but the doctor said it wasn't anything. I think it's okay."
Nadal will have to be closer to his best against his next opponent, 15th seed Mikhail Youzhny, who has won their last two meetings.
"He's one of the more difficult players for me," admitted Nadal.
"I must focus on me, play my best tennis. If I do that I can win. If I don't he will have a good opportunity to beat me."
STRONG FAVOURITE
While Nadal was always a strong favourite to beat Bracciali, Roddick had seemed at risk of going out against claycourt specialist Gaudio.
The American, who was playing his first tournament since pulling out of the Miami Masters with a hamstring injury in March, dominated the early stages of his match but had to fight hard to seal the second-set tie-break.
Gaudio -- who has slipped to 71 in the rankings since winning Roland Garros in 2004 -- saved four match points before double-faulting to gift Roddick a fifth, which he converted by coming into the net to tuck away a winning volley.
"This is my most challenging surface, so if there was ever a time to beat him and be a little proud, I guess it's on this surface," said Roddick, who next plays Juan Ignacio Chela.
Roddick's record of one quarter-final in his last four visits to the Italian capital makes him an unlikely candidate for the title. Djokovic, however, remains a good outside bet.
The 19-year-old Serb arrived in Rome full of confidence after winning last week's claycourt event in Estoril -- his third title of the season.
He gave a resilient performance against Soderling, holding off a series of break points before grabbing a decisive break in the eighth game of the final set.
Sixth seed Fernando Gonzalez and seventh seed Tommy Rodredo also progressed on a good day for the top-ranked players.
There was disappointment, however, for ninth seed James Blake, who lost to Chilean Nicolas Massu, and 13th seed Richard Gasquet, who crashed out 6-4, 6-7, 6-4 against Italian wildcard Filippo Volandri.
Results, 2nd round:
Potito Starace (Italy) beat 16-Juan Carlos Ferrero (Spain) 6-2, 3-6, 6-2
4-Nikolay Davydenko (Russia) beat Marat Safin (Russia) 7-6(4), 7-5
Gilles Simon (France) beat Guillermo Canas (Argentina) 7-6(4), 6-4
2-Rafael Nadal (Spain) beat Daniele Bracciali (Italy) 6-4, 6-2
Nicolas Massu (Chile) beat 9-James Blake (US) 7-6(3), 7-5
7-Tommy Robredo (Spain) beat Oscar Hernandez (Spain) 7-5, 4-6, 6-1
Juan Ignacio Chela (Argentina) beat Igor Andreev (Russia) 7-5, 7-5
Filippo Volandri (Italy) beat 13-Richard Gasquet (France) 6-4, 6-7(5), 6-4
15-Mikhail Youzhny (Russia) beat Olivier Rochus (Belgium) 7-6(7), 6-3
6-Fernando Gonzalez (Chile) beat Dmitry Tursunov (Russia) 6-2, 6-1
Marcos Baghdatis (Cyprus) beat Radek Stepanek (Czech Republic) 3-6, 7-6(5), 6-2
5-Novak Djokovic (Serbia) beat Robin Soederling (Sweden) 3-6, 6-4, 6-3
12-Tomas Berdych (Czech Republic) beat Albert Montanes (Spain) 7-6(5), 6-3
3-Andy Roddick (U.S.) beat Gaston Gaudio (Argentina) 6-1, 7-6(8)