By NESTOR F. SEBASTIAN

Copa Libertadores returns to action and its semifinalists will be determined this week as the second legs of he quarterfinals get underway this week with all four matches pretty tight, making the away-goal rule crucial. Brazil has a great chance of having a champion with four of its representatives in the final eight, which would give it its first title since 2006 when Internacional won it.

Tonight, Nacional of Uruguay, which are strangely dealing with a bout of flu among 10 players, will host Brazil's Palmeiras (6:20pm ET) with one goal apiece entering the return match, thanks to an 80th-minute equalizer 18-year-old Santiago Garcia. However, Palmeiras has overcome adversity throughout the tournament and with top forward Keirrison and a solid back line, the Brazilians shouldn't be discounted.

Later on, Venezuela's Caracas visits Brazil's Gremio (8:50pm ET) with this contest also knotted at one goal each. The Brazilians' 18-year-old attacking midfielder Douglas Costa will look to impress as reports claim Manchester United are ready to swoop in for him. Caracas, who got a goal from former New York Red Bulls player Gabriel Cichero, knows it has a tough assignment in Brazil if it wants to be the first Venezuelan team in the tournament's semis.

On Thursday, Argentina's Estudiantes de la Plata welcome's Uruguay's Defensor Sporting (6:30pm ET), the recently-crowned champions of the Uruguayan Clausura. The Argentines, led by Juan Sebastian Veron, got a precious 1-0 victory in Uruguay in the first leg and are seeking their fourth Libertadores title.

The final match is an all-Brazilian affair (9pm ET) pitting Sao Paulo and Cruzeiro in a salivating contest, with Cruzeiro visiting with a 2-1 advantage and seeking only its second win in 10 matches against the Brazilian champions. Cruzeiro striker Kleber is another Brazilian trying to fend off distractions with claims that Liverpool have tabled an offer for him.

What do you think of the Brazilian dominance? Not surprised? Or do you think we will see a champion from Argentina, Uruguay or even Venezuela? Share your thoughts.