Britain's world number four Tim Henman won his opening match at the Swiss Indoors tennis tournament with little difficulty on Wednesday, beating Frenchman Antony Dupuis 6-3, 6-4.

Breaking Dupuis once in each set, Henman was in control throughout the match and apparently back to almost full strength following last week's set-back at the Madrid Masters.

Diagnosed with a magnesium deficiency following his tired performance in the Spanish capital, Henman has now been put on magnesium tablets.

"This magnesium business has all been a bit strange, but I do feel better now," Henman said after Wednesday's win. "Last week I was really struggling and the doctors could only say that it might be this, or it might not be. But it feels like my energy levels are getting back up."

Henman faces South African qualifier Wesley Moodie in the second round, knowing that a good run in Basel may be necessary if he is to qualify for next month's Masters Cup in Houston.

The lucrative season-ending finale will be contested by the seven top players in the Champions Race standings, along with Argentina's Gaston Gaudio who receives an automatic place as this year's French Open winner.

GREAT YEAR

Despite being ranked fourth in the ATP rankings, Henman is seventh in the ATP Champions Race and could still be overtaken by America's Andre Agassi and Argentina's David Nalbandian.

"If I play like I played today, then I have a good chance to qualify," Henman said on Wednesday. "But I'm just going to concentrate on my own performances rather than worry about what everyone else is up to.

"The way I'm looking at it, I'd love to qualify, but if I don't I'm not going to let it detract from the great year that I've had."

Henman, who reached the semi-finals at both the French and U.S. Opens this year, has an impressive record in Basel, having won the title here in 1998 and 2001.

He has also made it to at least the quarter-finals in his seven previous appearances at the 989,750 euros event.

Seeded second in Basel this year, Henman had his title chances boosted on Tuesday when Swiss top seed and world number one Roger Federer was forced to pull out of his home city tournament because of injury.

Federer, who ruptured a thigh muscle fibre during a practice session, is expected to be out of action for 10 to 14 days.

Chilean eighth seed Fernando Gonzalez also made an early exit from the tournament on Wednesday, crashing out to French qualifier Jerome Haehnel 6-3, 6-4.

Chile's Olympic gold medallist Nicolas Massu had no such problems in his first round match with Swiss qualifier Michel Kratochvil, winning 6-3, 6-2.

German sixth seed Rainer Schuettler booked his second round place with a 6-3, 6-4 win over Spain's Rafael Nadal.