RIO DE JANEIRO — Flamengo scored four goals in a superb second half, demolishing Gremio 5-0 on Wednesday and qualifying for the Copa Libertadores final for the first time since 1981.

The win in South America's equivalent of the Champions League came after the two sides drew the first leg 1-1 in Porto Alegre and extended Flamengo's unbeaten run to 18 games in all competitions this season.

It set up a final against the Libertadores holders River Plate in a Brazil-Argentina final scheduled for Santiago, Chile, on Nov. 23.

The Argentine side lost 1-0 to Boca Juniors on Tuesday but qualified for the final 2-1.

"We have written our names in the page of Flamengo’s history," said Gabriel Barbosa, the man of the match whose second half double takes him to the top of this season's Libertadores goalscoring chart.

"Obviously there is another game to go but we are happy to be in the final."

Close to 70,000 fans packed the Maracana stadium in Rio, where Bruno Henrique scored the opener three minutes before halftime, hammering home from close range after Paulo Victor parried a shot from Barbosa.

Barbosa got the second goal two minutes into the second half with a fierce shot from 16 meters out after Gremio failed to clear a corner kick.

The striker, on loan from Inter Milan, got Flamengo's third from the penalty spot 10 minutes later and the goal, which made him the tournament's top scorer this season, was a knock-out blow for the visitors.

Centre half Pablo Mari made it 4-0 after 67 minutes when he headed home from a corner kick and his defensive partner Rodrigo Caio added another four minutes later.

Gremio, winners of the competition in 2017 and semi-finalists last year, could do little against a far superior side for whom Barbosa and Bruno Henrique were outstanding up front.

Flamengo, who also sit top of the Brazilian first division, last won this title in 1981, when Brazilian World Cup stars Zico, Junior and Leandro were playing for the side. — Reuters