Paradorn, who reached the semi-final here in Indian Wells, California, last year, lost to Janko Tipsareic of Serbia and Montenegro 6-4 6-2 in his first match after a two-month wrist injury lay-off.

The early exit will change the status of the former world No 9, who will no more be the country's top-ranked player when the ATP rankings are updated next week. Danai Udomchoke will replace Paradorn, who dominated the local tennis circles for a long time.

Paradorn, who was rusty throughout his match and who has been suffering from tendonitis since January, will plummet from 52 to somewhere outside the top 80, which will be his lowest position in several years. That means Danai, now at 77 in the world, will be the top Thai player next Monday.

In the women's singles second round, Tamarine Tanasugarn was no match for 21st seed Samantha Stosur of Australia as she succumbed in straight sets 6-3 6-4.

Meanwhile crowd-pleaser Andy Roddick began the chase for his fifth career Masters Series title with a 7-6 (7-5) 6-4 opening win over Feliciano Lopez.

The American third seed took victory on the day of the largest attendance in tournament history, going through in less than 90 minutes.

Roddick fired 15 aces to improve his record to 15-3 on the season. The former No 1 is hoping to carry forward momentum from a Memphis semi-final last month and a final four at the Australian Open.

The seed never faced a break point as he stayed in control over the Spaniard.

Rafael Nadal won his 10th match of the season, using his bludgeoning forehand to good effect in a 6-3 7-6 (7-3) win over Frenchman Arnaud Clement to join Roddick in the third round.

The Spanish world No 2, beaten last week in the quarter-finals in Dubai, is still in the hunt for his first title since lifting a second Roland Garros crown in June. His last final was Wimbledon 2006 against Roger Federer.

Last year's semi-finalist began against Clement with a love game to break but found the terrain rougher after taking the first set.

Nadal fired 10 aces and saved five of the six break points he faced.

"I feel very good with my forehand," said the winner. "I've been practising very well, especially with my forehand. This was one of my best matches for it. Ten aces don't happen every day for me. My forehand felt the best since 2005."

Clement, ranked 53rd, still gave the Spaniard a late fright, breaking as Nadal served for the match leading 5-3 in the second set. After taking the contest into a tiebreaker, Nadal finally prevailed. "I'm looking forward to Indian Wells and Miami after," said world number 2 Nadal.

"These two tournaments are very important for every player. They're the two first Master Series of the season. There are a lot of points, and I'm gonna try my best to play very good tournaments."

After three months away with injury, two-time finalist Tim Henman found his comeback stalling as he went down to modest Czech Jan Hernych 7-5 3-6 7-5 in a first-round disappointment.

Henman only returned to play last week in Las Vegas after dealing with a knee injury he suffered in November at his last event in Basel. The 32-year-old lost title matches in the desert in 2002 to Lleyton Hewitt and 2004 as Federer lifted the first of three consecutive trophies.