OXBORO, Massachusetts -- For Sunday Oliseh, the agony was almost too much to bear.Once the final whistle had sounded, he fell to his knees, drained and emotionally exhausted. For two hours, the 19-year-old had played the game of his life. But a single mistake in 120 minutes spelled the difference between Nigeria's going on to the quarterfinals or going home to Lagos. And Oliseh knew he had made that mistake. Italy's Giuseppe Signori, the leading scorer in the Italian League for the last two seasons, came over to console the teenager, helping him to his feet and exchanging shirts in the time-honored soccer tradition. But it was not Signori's shirt that Oliseh should have taken home as a souvenir. The one he really should have been given belonged to Roberto Baggio, the Italian superstar whose two goals condemned the African champion to a 2-1 defeat Tuesday.And it was the first of those goals, with only 106 seconds left in the game according to the stadium clock, that will haunt Oliseh.Clemens Westerhof, Nigeria's Dutch coach, had assigned Oliseh, from Agbor in Bendel state, the most difficult task of all Tuesday -- guarding Baggio, who was voted the world's best player last year. On the surface, it seemed a mismatch of monumental proportions. Baggio, the 27-year-old superstar from perennial Italian champion Juventus being kept in check by a youngster who until recently was playing his club soccer for modest FC Liege in Belgium? No contest.But Oliseh did his job in superb fashion, shadowing Baggio like a hawk over a hare. Every time the ball was passed to Baggio, there would be Oliseh to either sprint in and intercept the pass or to tackle the ball away.Finally, in the dying minutes, with Nigeria clinging desperately to a 1-0 lead that would have sent the three-time world champions down to one of the most ignominious defeats in Italian soccer history, the fateful play unfolded. The ball was played into the Nigerian penalty area, scant yards from the net. Italy's Roberto Mussi found himself with the ball at his feet and only Nigerian goalkeeper Peter Rufai to beat. Oliseh spotted the danger and sprinted in to tackle Mussi. The Italian side-stepped the challenge and passed the ball to Baggio, who was momentarily unguarded. Baggio scored, the game was tied and Italy was saved.Oliseh really had no choice but to leave Baggio and pressure Mussi, but because Oliseh missed his tackle, Nigeria failed. Italy went on to win the game in overtime on Baggio's penalty.