Playing the American qualifier, Alex O'Brien, in the first round at the Northern club in Didsbury, he squandered an impressive advantage in a 1-6, 6-4, 6-0 defeat that lasted an hour and a half.
Ahead by a set, Henman, the British No 7 from Oxford, had two break points to take a 5-4 lead in the second set. But when he failed to convert those, he slumped at an alarming rate, losing eight games in succession.
''It was a disappointing end,' he conceded, while implying the result was down to inexperience. 'There'll be a lot of matches and a lot of defeats like that. He started running round my second serve and putting pressure on it and I started to slow my first serve down a bit to make sure I got it in. Maybe that was a mistake.'
To be fair to Henman, who has risen 214 places to 158 in the world rankings this season, he was meeting a man ranked 50 places above him and who has five years advantage in terms of age.
There was also an element of fortune about the first of O'Brien's break-saving volleys at the match's turning point, the ball hitting the net cord before bouncing apologetically into the court.
The defending champion and fifth seed, Australia's Jason Stoltenberg, surrendered the second set to love to Austria's Alex Antonitsch but recovered to win 7-6, 0-6, 6-2.
Michael Stich had a comfortable 6-3, 6-4 victory over Nicolas Pereira, of Venezuela, in the first round of the Halle men's tournament in Germany yesterday.Reuse content