Tim Henman opened his Dubai Open campaign with a straight-sets win over Feliciano Lopez but fellow Briton Greg Rusedski crashed out to Andre Agassi.
Henman has been struggling with a back injury in recent months
Henman, who reached last year's quarter-final, beat Spaniard Lopez 6-2 7-6 (8-6) for a place in the last 32.
He will now play last week's Rotterdam Open winner Radek Stepanek or John van Lottum in the second round.
Rusedski, meanwhile, lost his first set on a tie-break, 7-4, before Agassi eased home 6-0 in the second.
Wildcard Henman was delighted with his win and said: "I have had so many problems with my bad back that when I get out there and actually feel healthy I want to take advantage of it."
The new British number three fought back in the second set after Lopez served for it at 5-4 and needed four match points to finish the job.
"I think one aspect of it was how calm I was on those important points," said Henman.
"And the back feels all right, too, so I'm very pleased."
Rusedski has lost eight of his 10 career matches against Agassi and was left to rue a telling service error early in the second set.
"In the first set I played pretty good tennis and just missed out on one or two points," he said.
"But all of a sudden in the second I served a double fault on break point and then Andre played pretty well and it was all over.
"If I'd had a good first game in the second set it might have been a lot tighter."
Rusedski admitted grass courts now offer his only real chance of success against such high-quality opponents.
"The slowing down of the balls makes it a lot harder for serve-volley players like me," he said.
"It means that if you're a fraction off you get punished. I'm looking forward to the grass season where the conditions will suit my game more."
Fourth seed Agassi is playing in his second tournament of the season after reaching the quarter-finals of Florida's Delray Beach tournament in early February.
And the 35-year-old admitted he is still being troubled by the ankle injury that kept him out of the Australian Open.
"It's still not perfect and it was bad enough to make me miss Melbourne," said the American veteran.
"But I'm really glad I got through as I really enjoyed playing here last year."
Among the other first round matches at the Dubai Tennis Stadium, Russian Igor Andreev overcame Andreas Seppi of Austria 7-6 1-6 6-4.
Czech Robin Vik defeated Yugoslav qualifier Janko Tipsarevic while two-time quarter-finalist Rainer Schuettler knocked out fifth-seeded Spaniard David Ferrer.