They could well have met in the ring at The Pyramid in Memphis. It is rather appropriate, though, that Maurice Greene and Tim Montgomery are due to settle their differences – for the time being at least – at the Olympic Stadium in Athens. Their scheduled meeting in the Grand Prix event there tomorrow night could be just the first of a series of needle matches leading all the way to the Olympic 100m final in the Greek capital in 2004.

They might not have become embroiled in a spat quite like the Tyson-Lewis press conference brawl in New York in January, but the American sprinters are developing an intensity of rivalry that is threatening to put some clout back into the battle for the title of the world's fastest man. For four years now, since he won the first of his three world 100m titles, Greene has been the undisputed champion. For the first time, though, the Kansas Cannonball is now being challenged by the emergence of a serious contender.

Montgomery beat Greene in Eugene last summer, won the United States title after Greene withdrew at the quarter-final stage, clocked the joint second fastest time ever for the 100m (9.84sec in Oslo, compared to the 9.79sec Greene recorded in Athens three years ago) and ran Greene a close second in the World Championship final in Edmonton in Canada. Having shown signs of walking the walk last year, the 27-year-old South Carolinan has been talking the talk of late, telling the world that he has Greene running scared and that he will take his scalp and his world record too.

He even told Greene that he was going to beat him when the pair lined up for the final leg of the 4 x 100m at the Penn Relays in Philadelphia in April. "Maurice came up to me and gave me his vision of the race," Montgomery recalled. "I gave my version of what the race was going to be. My vision turned out to be the correct one."

Indeed, it was round one of the summer to the challenger. Montgomery's colleagues in the USA Blue team gave him a slight lead at the final baton exchange and Greene was unable to close it, shaking his head in an unfamiliar act of despair as he crossed the line second.

Montgomery would argue that he has taken round two as well, Greene having withdrawn on the eve of their scheduled meeting at Osaka in Japan last month, citing an injured knee. Montgomery also took some alleged sledging by Greene and his training partner Ato Boldon in the build-up to the meeting as a back-handed compliment.

When asked about motivation last week, Montgomery said: "All I do is turn on my computer and read some of the things Maurice Greene said about me. Maurice and his group have separated themselves. They never include the rest of us. When they have an interview it's all about Maurice and Ato Boldon. Maurice says: 'There's no one else to race against. No one can beat me.' He just plays with us like it's nothing.

"It's getting very intense in the 100m, very intense. It's like no one likes each other. It's not going against the British or the Russians. The American sprinters are going against each other. We're declaring war on each other.

"I have already had my first breakthrough. I saw fear on Maurice's face at the Penn Relays that I haven't seen since he has been running. He is the greatest 100m runner of all time. Every time he steps on the track he's under 10 seconds. But I am sure I will catch him. Positively, I'll catch him.

"I study Maurice's first 30m and Carl Lewis's second half. I mix the two and now I have come up with the biggest package. I am just waiting for everything to come together, like baking a cake. I know I'm going to see 9.7. It's just where I'm going to see it."

Athens tomorrow night would be the perfect stage for Montgomery, who trains with Marion Jones in the group of sprinters groomed by Trevor Graham at Raleigh, North Carolina. It would be the perfect stage for Greene too, though. "Athens is a very special place to me," he said. "It's where I won my first world title and where I broke the world record. It's like a second home to me."

Having retained his world title in 9.82sec in Edmonton last summer, limping across the line with an injured hamstring, Greene is convinced that he can break the world record himself. "I know what I'm capable of doing," he said. "I know that if I stay healthy I can break my world record."

The world and Olympic 100m champion is also convinced that he can see off the challenge of the fast-emerging Montgomery. "There is a rivalry there," Greene admitted. "But do I worry about him? No."