Qatar Open, Doha
Third seed Mark Philippoussis began 2004 in the worst possible fashion, crashing out in Doha to defending champion Stefan Koubek.
The Australian took the first set, but lost his way afterwards as he crashed to a 3-6 6-1 6-4 loss.
Unseeded Koubek admitted he almost lost the third set and the match.
"I was playing well and was on my way to victory but for some reason I lost my composure and felt very nervous," he said.
"I lost many matches like this last season and I thought I might lose this one too. Maybe it was the pressure of being the defending champion."
Earlier, top seed Andy Roddick began in solid fashion, beating Nikolay Davydenko of Russia in straight sets.
The 21-year-old world number one took just 67 minutes as he overpowered his unseeded opponent to triumph 6-3 6-4.
"It was a good workout. It is always difficult to start after a break. But I would say it was a comfortable win for me," the US Open champion said.
"The match might not have been spectacular but I did what I was supposed to do and I am happy."
The American will play the winner of the match between Sweden's Jonas Bjorkman and Czech Radek Stepanek in the second round.
There was bad news for Morocco's sixth seed Younes El Aynaoui and Chilean number five seed Nicolas Massu, who both crashed out in straight sets.
El Aynaoui lasted little more than an hour as French wild card entry Nicolas Escude won 6-3 6-0.
"My goal for this year is just to be able to get on the court regularly," said Frenchman Escude, who was plagued by injury in 2003.
Massu did no better against Croatia's Ivan Ljubicic who won 6-3 6-3.
Fourth seed Sebastien Grosjean overcame Germany's Markus Hantschk 6-1 7-5.
France's Wimbledon semi-finalist had a few wobbles, slipping up when serving for the match in the second set at 5-3, but found his rhythm.
Fifth seed Felix Mantilla of Spain beat Jan Vacek of the Czech Republic 6-3 7-6.
And Argentina's Juan Ignacio Chela triumphed over Belgium's Christophe Rochus 6-3 3-6 7-5.
Tata Open, Madras
Defending champion Paradorn Srichaphan of Thailand coasted into the second round in Madras on Tuesday.
The 24-year-old second seed brushed aside Spain's Albert Montanes 6-1 6-3 in just 45 minutes.
"Playing the first match of a new season is always tricky. It's difficult to find the rhythm, but I was hitting well and accurately," said Srichaphan.
"One's never too confident before the first game of the season, but this was a good way to start."
In 2003, Paradorn clinched the title without dropping a set in the entire tournament.
Top seed Carlos Moya of Spain had few troubles, beating qualifier Noam Okun of Israel 6-3 6-4.
Moya, ranked seventh in the world, stormed to a 5-0 lead in the opening set, before surviving a slight wobble.
Okun lifted his game in the second, but was broken in the fifth game by Moya, who will now meet Paul Goldstein of the USA in the second round.
Third seed Sjeng Schalken of the Netherlands overcame a rusty start to win 6-4 7-5 against Thai qualifier Danai Udomchoke.
And fourth seed Thomas Robredo of Spain, beat Russia's Dmitry Tursunov 7-5 6-7 6-4.
AAPT Championships, Adelaide
Rain held up Greg Rusedski on his return to action in the first round of the AAPT Championship.
Rusedski played just 26 matches last year
The British number two was on course for victory, leading Switzerland's Stanislas Wawrinka 6-4 3-1, before the weather intervened in Adelaide.
Rusedski, 30, has been out since losing both of his singles matches in
September's Davis Cup loss in Morocco.
He damaged his back in that tie to cap a disastrous year which also saw him suffer foot and knee problems.
His match against Wawrinka will be continue on Wednesday.
In other matches, Frenchman Arnaud Clement and Ecuador's Nicolas Lapentti eased into the second round.
Eighth-seeded Lapentti beat Georgia's Irakli Labadze 7-5
6-1 in the opening match on centre court before
third-seeded Clement beat Romania's Victor Hanescu 6-3 6-2.
Italy's Davide Sanguinetti took 42 minutes to beat German qualifier Daniel Elsner 6-1 6-1, while Slovakian Dominik Hrbaty defeated Frenchman Julien Benneteau 6-1 6-4.