Rivaldo and Brazil couldn't get past a pesky Ecuadorian team in their World Cup qualifier.(AP)

The Barcelona midfielder was substituted midway through the second half and the veteran striker missed his team's three best chances.

The goal was the Delgado's fifth goal of the qualifying competition and possibly the most important in his country's soccer history.

A heroic double save by Ecuador goalkeeper Jose Cevallos in the 89th minute completed Brazil -- and Romario's -- bad day and the final whistle set off massive celebrations at the Atahaulpa stadium.

Brazil remained second in the South American group with 20 points from 11 games but are now only one ahead of Ecuador.

Ecuador are considered one of the weakest soccer nations on the continent and their highest achievement was a modest fourth place at the Copa America the country hosted in 1993.

Previous results against Brazil include defeats of 9-1, 9-2 and 7-1.

The first half was a cautious affair. Ecuador looked wary of the threat posed by Brazil's attack and the visitors worried about the effects of the altitude, Quito lying at 2,800 metres above sea level.

Brazil arrived in Quito only four hours before kick-off in an attempt to lessen the effects of the rarefied air but never settled and had two warnings in the first half.

On the half hour, Aguinaga chipped the ball over the defence and Kaviedes shot across the face of the goal. In a similar move just before halftime, Edison Mendez sent Kaviedes clear and he lobbed the ball over Rogerio Ceni but, agonisingly for Ecuador, his effort bounced off the top of the crossbar.

But the breakthrough came four minutes into the second half when Kaviedes dribbled past three defenders in the penalty area and passed to Delgado who slid the ball into the net.

Ecuador dropped back into defence but Brazil rarely looked threatening.

Their despair increased to the point that captain Rivaldo was substituted in the 64th minute and replaced by Luizao.

Romario had a clear chance to equalise in the 66th minute but his shot struck the outside of the post.

He had almost missed an excellent chance early on when Juninho Paulista sent him clear of the defence but a poor first touch allowed goalkeeper Jose Cevallos to make a diving save at his feet.

In the last minute, Romario saw a diving header at point blank range brilliantly saved by Cevallos, who also managed to stop the follow-up.