Barcelona: Lleyton Hewitt returned to the Barcelona Open for the first time since 2002 with an opening-round 6-4, 4-6, 6-2 defeat of Turk Marsel Ilhan.
But two more seeds were sent out on the clay on Day Two, with Frenchman Jeremy Chardy upsetting Spanish number 14 Albert Montanes 6-3, 7-6 (7/1) and 92nd ranked home qualifier Daniel Gimeno-Traver defeating Argentine number 10 Juan Monaco 6-2, 3-6, 6-2.
Simone Bolelli secured an upset when 2004 winner and ninth seed Tommy Robredo had to quit with a back injury to give his Italian opponent a 6-7 (7-9), 6-4, 3-1 win.
Spanish number 16 Feliciano Lopez had the same luck when he beat Oleksandr Dolgopolov 6-3, 3-0 as the Ukranian could not finish.
Second seed Robin Soderling made a spectacular clay season debut, coming back from a break down in each set to beat Juan Ignacio Chela 7-5, 7-5.
It was a day of drama off-court as Rafael Nadal detailed his reasons for withdrawing as a precaution from one of the events which is closest to his Spanish heart and where he has won the last five editions.
"It`s been a tough year," said the world number three, who expressed his disappointment at being forced to let down his home club and public.
"My goal is to remain healthy and fit," said a player well acquainted with injury absences due to the delicate state of his knees.
Nadal said that three straight weeks of elite clay events - Monte Carlo, Barcelona and Rome - were too much in too short a period, another knock at the ATP calendar which he has long complained is helping to cause player injuries and burnout.
"I`m being as cautious as possible, I want to have as long a career as possible," said Nadal, who lost his only match in Barcelona in 2003.
"Tennis isn`t like football, you don`t know how many matches you will play."
He is expected to return for Rome next week.
The 12th-seeded Hewitt went missing for eight years at the Real Club de Tenis, where he challenged as world number one for a place in the 2002 final but lost his semi to eventual champion Gaston Gaudio.
In the intervening years, the former Wimbledon and US Open winner played sparingly on the spring European clay, due partly to his natural disposition for hardcourts and also later due to injuries which have included two hip surgeries.
But Hewitt showed no ill effects as he began his European clay season with the goal of doing well in the run-up to Roland Garros next month.
The Australian fired ten aces and broke six times against Ilhan, who could be the key to a possible upset of Britain in a do-or-die Davis Cup playoff in July for his nation.
Hewitt saved four of the five break points he faced in a victory lasting just under two hours to move into a second-round contest against Argentine Educaro Schwank.
The Australian will next face Argentine Eduardo Schwank Wednesday.
"It`s good to get through the first match here," said Hewitt. "I`ve played Schwank before on grass at Queen`s but I expect he`ll be much tougher to play against on clay here."
The 29-year-old Aussie, who underwent right hip surgery on January 29, is playing in his second tournament back after Houston, where he reached the quarter-finals before losing to Juan Ignacio Chela.
Hewitt`s win marked only his sixth of an abbreviated season against three losses.