The 13th-seeded Aussie, who had a clean 8-0 record lead over Henman prior to the match, saved five set points before surrendering the first set and conceded a break early in the second, to hand the Briton his first win against him and a ticket to the third round.

Henman, whose ranking has slipped to 56 in the world, had also eliminated former world number one, Marat Safin in the first round in Miami.

"I played a good match," the former world number four was quoted as saying by the tournament’s official website.

"I think my match against Safin was much cleaner and of probably a higher quality but this was a case of different conditions against a different opponent. This was more satisfying," added Henman.

The 31-year-old Briton, who reached the quarterfinals in Miami last year, will have to match his last year’s performance at the Masters Series event to avoid a further descent down the rankings.

Hewitt, who also suffered a third round exit from the Masters Series event at Indian Wells last week, said that the tough weather conditions and Henman’s victory over Safin earlier in the tournament were among the factors attributing to his defeat.

“I feel like I didn't hit the ball great out there today. You know, conditions aren't easy, though. You definitely got to play percentage tennis. The ball is swirling around out there,” said the two-time Grand Slam champion.

“In these tournaments these days there are very few, you know, easy matches, especially when the top guys have byes as well.”

“Obviously, Tim beating Marat the other night, that gives him a lot of confidence, beating a guy, you know, who's one of the best ball strikers out there,” added Hewitt.

Henman next takes on Simon Greul, who upset 17th-seeded Dominik Hrabty 7-6 (6), 6-3.

Other Saturday winners include 19th-seeded Sebastien Grosjean, 11th-seeded David Ferrer and 9th-seeded James Blake.