Ivan Zamorano of Inter Milan made an immediate mark on the Olympic Games yesterday with a 21-minute hat-trick in Chile's 4-1 win over Morocco at the Melbourne Cricket Ground.

Gold medal favourites Brazil started their campaign with a stuttering 3-1 win over Slovakia in Brisbane.

In the other matches Japan came from behind to beat South Africa 2-1 at Bruce Stadium in Canberra, while Spain, another possible medallist, overcame South Korea 3-0 at the Hindmarsh Stadium in Adelaide.

But the night belonged to Zamorano who scored three of Chile's four goals against the Moroccans and had a hand in the other. Morocco played most of the Group B match with 10 men after defender Adel Chbouki was sent off in the sixth minute.

Brazil fell behind to a Andrei Porazik goal after 26 minutes but equalised four minutes later through Alex. Marian Cisovsky put through his own goalo to give Brazil the lead on 68 minutes before Alex made sure of the points with his second in the closing minutes.

Japan fell behind after 31 minutes when Siyabonga Nomvethe sent a brilliantly-executed looping header into the far corner of the net to put South Africa ahead after superb approach work by Benni McCarthy. South Africa allowed Japan back into the match when Naohiro Takahara equalised with a header in first half injury time. Takahara was on hand again 11 minutes from time to score the winner. Spain, loooking to repeat their 1992 gold-medal winning performance in Barcelona, were far too strong for South Korea and never looked back after going ahead in the 10th minute when Spanish skipper Toni Velamazan volleyed home. Jose Mari added the second after 26 minutes with a close-range effort while Xavi made the points certain with the third goal after 37 minutes.