Henman, now ranked 14th, is firmly the underdog in the third-round match at the Australian Open. Chang beat Pete Sampras and Boris Becker only last week and was runner-up here last year.
Though only two years older at 24, Chang has a massive advantage in experience. He won the French Open when he was 17, reached the final of the US Open last September and the final here last year.
What Henman has going for him is supreme confidence at the moment and the knowledge that he hits the ball harder than Chang, especially on the serve, and has the sort of all-court game which most troubles his opponent.
The match will be given special coverage by the BBC in an extra programme tonight. The third-round encounter will be shown on BBC2's regular Sport on Friday programme (1410-1555), but will be replayed later on an International Tennis special (1800-1900) on the same channel. Eurosport will feature the game live at 9.15am.
Thw world No 1, Pete Sampras, gives Henman a chance: "It is going to be a good test for Henman. Chang is not an easy guy to play and Henman is going to have to work hard, but the way he has been playing he has got a shot." Henman, however, has been beaten here already, going out of the men's doubles at the first hurdle along with the Dutchman Jan Siemerink.
Sampras reached the third round of the singles after a scare. The world No 1 was a set and a break down to the Romanian, Adrian Voinea, but got his act together to win 3-6, 6-2, 6-3, 6-2 in 109 minutes. He plays Australia's Mark Woodforde, who has twice held match points against him in the past.
Jim Courier threw himself into the River Yarra after both his previous title successes here, but if this year's championship continues as it has started for him the 26-year-old is unlikely to have the energy to do so again.
His two matches so far have both lasted five-sets and Courier has had to come back from 2-1 down both times. He beat the Czech Republic's Slava Dosedel 4-6, 6-2, 3-6, 6-4, 6-4 and said: "As long as I win I don't care how long it takes." He plays his fellow American Jeff Tarango.
The women's second seed, Arantxa Sanchez Vicario, spent only three minutes on court. She won the first game against Stephanie De Ville, then the Belgian pulled out with an ankle injury. Martina Hingis, the 16-year-old fourth seed and second favourite behind Steffi Graf, beat America's Lisa Raymond 6-4, 6-2 and described her play in the second set as "almost perfect".
The fifth seed Anke Huber, last year's runner-up, hit back from a set down to beat Italy's Francesca Lubiani in a match delayed for a day after Huber's mother was rushed from Flinders Park to hospital after collapsing.
Results, Digest, page 27