Riquelme, playing his farewell match with the Argentine club, scored with a well-placed shot from outside the area in the 69th minute and added another in the 80th minute on a rebound from a shot by Palacio.

"We played well in both matches and took advantage of the result in the first leg," said Riquelme, who was selected the finals most valuable player. "I'm very happy with the title. The fans deserved it."

Boca won the first leg 3-0 last week in Buenos Aires and could have clinched its fourth title in seven years even if it had lost by two goals.

Needing to score at least three time, Gremio pressed from the start, but could not finish its chances. Boca defended well to hold off the Brazilian attack.

"Our team made too many mistakes, just like in the first match," Gremio defender Lucio said. "All we can do is congratulate Boca players and move on."

The title moved Boca within one trophy of Argentine rival Independiente, which has a record seven. Boca's other titles came in 1977-78, 2000-01 and 2003.

"We knew we had a good advantage," Boca striker Martin Palermo said. "But we still had to play good enough to contain Gremio and their fans. After we scored the goals at the end everything was easier."

Boca also earns the right to play in FIFA's Club World Cup, which also will have European Champions League winner AC Milan. Boca beat Milan in 2003 when the club world title was only contested between the European and South American champions.