GUADALAJARA, May 22 (SW) - Boca Juniors and Fluminense are through to the semi finals in the Copa Libertadores, beating Atlas Guadalajara and Sao Paulo FC respectively.

After the 2-2 result in Buenos Aires last week, Boca faced a tough task at Atlas. But hero of the night was Martin Palermo with three first-half goals.

Atlas were mentally beaten and couldn't do anything about the situation. The Mexicans lost Bava to a red card in the 50th minute.

Fluminense turned around last week's 1-0 defeat by Sao Paulo, winning 3-1 at home thanks to a last-gap goal.

Washington had put 'Flu' ahead early on but Adriano levelled in the 71st minute.

A minute later though, it was Dodo to restore the home side's lead and Washington netted the decider in stoppage time.

Sao Paulo's Joilson was sent off in the 84th minute.

The other two semi finalists will be known tonight. America have a good chance of advancing after their 2-0 win over Santos last week, and anything is still possible at Liga de Quito versus San Lorenzo, who drew 1-1 in their first match.