Nervously does it for Tim and Greg

The Argentine factor again came perilously close to dishing Tim Henman's hopes of progress at the Ericsson Open in Key Biscayne. A qualifier from Buenos Aires, Agustin Calleri, extended Henman for two hours 20 minutes before finally capitulating 6-3 6-7 6-4.

So Henman moved into the third round to join Greg Rusedski, who managed to see off Andrei Medvedev 6-4 7-5 late on Friday despite comparing his service action to a car in urgent need of an MOT.

Apart from the worrying tendency to struggle against those who, like Calleri, lurk in the lower depths of the game, Henman also has something about players from Argentina these days. He lost to Guillermo Canas at the US Open last September and to Mariano Zabaleta in London last month. Now it is Zabaleta who stands between the British No 1 and the fourth round.

Calleri, who had surprised Marc Rosset in a Friday marathon 5-7 6-3 7-6, again demonstrated his stickability and steadiness. After Henman had taken the opening set with a break of serve in the eighth game, Calleri, whose parents own a liquor store, tasted the prospect of another huge success by winning the second set tiebreak 7-5.

Henman, however, was rock steady when it mattered in the final set, despite being the recipient of several dodgy calls from the line and overrules from the chair. In fact, he went to match point by returning a Calleri shot which was clearly out, but not deemed so officially, for a spectacular backhand winner down the line. For the first time Calleri sagged and dumped a forehand weakly wide.

It was Rusedski's good fortune that Medvedev was horrendously lax, permitting the British left-hander time to dwell on his shots and get away with it. Having now lost to Greg six straight times, Medvedev is in danger of acquiring the label Rusedski's Rabbit.

This is only Rusedski's fifth tournament since his footoperation last December, and there remains much rust to be shed. After the embarrassment of early defeat at Indian Wells last week he cited three areas where practice andimprovement were urgently needed - serve, volley and backhand, which doesn't leave a lot in his game classified as functioning normally.

Rusedski is much given to mood swings, and there were fears on Friday that if thevagaries of the weather didn't weigh him down, the long wait to get on court would. It was a day of swirling winds and heat, but by the time Rusedski finally buckled on the breastplate and marched into action night had long fallen.

His seven-hour wait finally terminated, Rusedski's agony began. The serve was again shaky - only four aces and six double faults - and the windinduced an extra cautionary factor into his thinking and moving. Instead of punching away the volleys and going for his returns, Greg was pushing them within reach of Medvedev.

So he was fortunate that the Ukrainian's form was a horror story. Medvedev never really recovered from dropping serve in the fifth game to a Rusedski forehand whichappeared to clip, or possibly just miss, the baseline. No call came, the game was awarded to Greg and Medvedevderided the decision loudly as "a f...ing joke", followed byseveral more decidedly audible obscenities which did not incur the deserved penalty.

Eventually Medvedev fell to cursing in Ukrainian andattempting to stem the Rusedski advance. He saved one set point with an ace but the first set was wrapped in 34 minutes and the second would rapidly have gone the same way if the British No 2 had not frittered away five break points.

There was a moment of alarm when Rusedski's continued fallibility on the smash and volley led him into danger and he had to scramble around to ward off three set points. That crisis survived, Greg belatedly assembled his skills in more or less recognisable order, briskly broke the Medvedev serve and clung on to his own delivery to march forward to a third-round meeting with the doughty Zimbabwean, Byron Black.

As Henman had done a couple of days earlier, Rusedski forecast some ugly, scuffling matches. "This place is a challenge. It's not always the person who plays the prettiest tennis here who ends up winning, it's the person whoperseveres and manages to hang in there."

Rusedski pronounced himself satisfied with the quality of his ailing backhand and volley, though some observers did not share his optimism, but he readily - and rather surprisingly - conceded his game is a long way from where he wants it to be, saying he was nowhere near the heights of 1997, when he was runner-up at theUS Open.

Asked to nominate marks out of 10 for his serve, he replied: "Six-and-a-half to seven. It's just a question of practice now, but with the tennis I am playing right now I won't be able to win a Grand Slam. It's also harder to hit aces because every year the balls get slower.

"The trouble is, I just expect my serve to be there, the way it was towards the end of last year. It is like stepping into your car, you don't really think about it. Unfortunately, my gear shift is crackling around a little bit. I need to get an MOT. I know what I am doing wrong. I am tossing the ball a little too far in front and throwing myself off balance." Perhaps he will find a fair, following wind for today's clash with Black.