"Can we call him the Phenomenon now?" barked the Italian commentator Bruno Pizzul in his demented 1950s headmaster-style voice. Ronaldo had just scored the goal of the season despite the most unwelcoming conditions Moscow could muster.

The weather was so unforgiving that the 1997-98 Uefa Cup semi-final second leg between Spartak Moscow and Internazionale nearly didn't happen. Hours before the game, the pitch was covered in 30cm of snow. It took half the local police force to shovel it off for the game to go ahead. By kick-off the saturated playing surface, bordered by a wall of grubby grey snow, was a two-tone mess of tired looking grass and mud with a curious tinge of yellow. If that weren't enough, a thin covering of ice complicated matters further. Despite being 2-1 up from the first leg, Inter, considered by many a team of divas, were not happy. "It was very cold and the pitch was impractical for football," sniffed the trundling but dependable Argentinian Javier Zanetti.

Some pundits felt Ronaldo shouldn't even be risked on such a perilous surface, but the Brazilian started next to Ivan Zamorano in Gigi Simoni's 1-3-4-2 formation. "Ronaldo is a phenomenon — even here he can entertain us," said the Inter icon and journalist Sandro Mazzola with a glint in his eye. Wearing a thick headband to keep his ears warm, Ronie looked more village idiot than world star.

The frozen Italians struggled lackadaisically through the first half. The bustling, agricultural left-back Taribo West couldn't handle the mobile Andriy Tikhonov and Zanetti looked uncharacteristically ill at ease on the wintery pudding of a pitch. Tikhonov gave the home side the lead after 12 minutes. The unflappable libero Giuseppe Bergomi and the goalkeeper and Dean Martin doppelganger Gianluca Pagliuca seemed the only Inter players who realised there was a game to played as the Russians got the scent of an away goals passage to the Paris final.

But, on the stroke of half-time, Ronaldo, who had jettisoned his comical headwear, took control. Spartak dealt poorly with a Francesco Moriero cross from the right and, after an outbreak of pinball, the ball fell to the Inter No 10, just outside the six-yard box. In the blink of an eye the former Barcelona man drove it into the net with a swish of his right boot. One chance, one goal. 

The defenders Miroslav Romanschenko and Dmitri Khlestov and the libero Dmitri Ananko had marshalled Inter's South American front two well until then but, buoyed by their goal, Inter were a different beast in the second half.

Inter's effervescent and classy midfield general Diego Simeone exerted more of an influence after the break, while Ronaldo and Zamorano began to find space. Drained of energy and belief, Spartak were powerless to stop Ronaldo killing the tie with a spark of genius after 76 minutes.

Between the centre-circle and penalty area, right of centre, Ronaldo called to Gigi Sartor, preparing to take a throw in. The right-back launched a long looping throw to the Brazilian, who controlled instantly and turned his marker before arcing his run towards the box. Nowhere near full speed, he already moved with the agility and zip of a Formula One car surrounded by pick-up trucks with punctures. Alert to the danger, Khlestov started a manic cross-field sprint from the right. By his speed and pumping arms the defender looked determined to smash Ronaldo out of the stadium and worry about the ball later. But he came off worse, bouncing off the deceptively strong forward. Ronaldo laid the ball square to Zamorano and continued his run. The clever Chilean's return was crisp and firm to avoid interception, but Ronaldo, on the edge of the area, took it into his stride easily. Faced with two more defenders in the box, the No 10 danced between them and through the mud at devastating speed. The keeper Aleksandr Filimonov raced out to confront the striker but fell for a typical Ronaldo feint and committed early. The supersonic assassin took the ball wide of him and sidefooted into the unguarded net.

The masterpiece, which won the game 2-1, was a nine-second demonstration of what put Ronaldo light years ahead of the rest: speed, strength, balance and skill. Even the Spartak fans applauded. The jubilant Inter players chased after and jumped on their teammate, the home players looked shell-shocked. The only man not to show any emotion in the stadium was the Scottish referee Hugh Dallas (also the only man in Moscow wearing short sleeves that night).

"There was mud and ice, but he had the gifts to rise above it. When he set off, no one could catch him," said Zanetti. Giacinto Facchetti, beloved captain of la Grande Inter, said, "He is decisive, just like Pelé and Maradona before him." The Inter president Massimo Moratti was suitably giddy, adding, "There aren't adjectives left to describe Ronaldo."

Gazzetta dello Sport's Enrica Speroni wrote that "early on the Brazilian looked like a very cold little boy, then he danced across that mangy setting as if it were a beautiful English meadow." In Spain, El Mundo Deportivo, perhaps yet to get over the player's acrimonious departure from Barcelona after only one season, said, "Once again we have seen that for Ronaldo impossibilities do not exist."

In the dressing-room Ronaldo gave his shirt to his coach as a souvenir. "It was a lovely gesture. I felt such joy when he gave it to me. I have still got that shirt, covered in mud. I have never felt the need to wash it," said Simoni. The man himself says, "Inter fans still talk to me about that goal. I felt like I was skating on ice, the opponents were slipping and sliding all over the place."

After personally delivering Inter to their fourth Uefa Cup final, Ronaldo didn't stop. In the Paris showpiece against Lazio the quicksilver Brazilian tortured the biancocelesti's princely centre-back Alessandro Nesta with his movement and quick feet. The nerazzurri won 3-0, Ronie scoring the final goal with another trademark pearl — zooming onto a throughball, producing a flurry of stepovers, rounding the prone keeper and sliding into the empty goal. It was his sixth goal in the 1997-98 Uefa Cup, and his 34th of the season in all competitions.

That 1997-98 Uefa Cup campaign was the last we saw of the 'pure' Ronaldo. Nike's 'R9' brand soon sprang into action, forgetting it had a human at its core. The striker changed his Inter shirt number from 10 to 9 and became the greatest commodity in world sport, selling everything from tyres to sunglasses. Rushed back from one serious injury after another, he lost two years of his career to chronic knee problems until making his comeback in the 2002 World Cup, scoring eight goals on the way to Brazil's victory. He was still the best of his generation and greatest goalscorer the World Cup has ever seen, but never again the turbo-charged extraterrestrial of Barcelona and that maiden season at the San Siro. 

For that reason, the diamond in the Moscow mud remains the purest expression of Ronaldo Luis Nazario de Lima's phenomenal talent.