Henman was unable to produce his recent good form

Henman served for the match at 6-5 in the third set, but Melzer broke to force a tie-break and came through 7-6 (7-3) 2-6 7-6 (7-4).

After losing a tight first set, Henman seemed in control when he took the second with two breaks of serve.

But he was unable to shake Melzer off, and the Austrian held his nerve in the decisive tie-break to clinch victory.

Beating Henman, it's huge... I feel great Jurgen Melzer

Henman said the blustery conditions contributed to his surprise defeat.

"I knew it was going to be a difficult day," said the Briton. "You just have to be out there and compete and know it's not going to be pretty at times.

"I played some good tennis under the circumstances. All credit to him. He played some great tennis."

Melzer added: "Beating Henman, it's huge. I feel great. I played my best tennis when it mattered and I won."