Los Pincharratas claimed a narrow victory in the first leg of the semi-final.
The Argentines started the stronger of the two sides and went ahead in the 14th minute when a quick Juan Sebastian Veron free kick found Leandro Benitez, who delivered an inch-perfect cross for Diego Galvan to head the ball home.
That early goal inspired Estudiantes and they went looking for a second goal, putting Nacional under constant pressure.
Alejandro Sabella's team played the better football in the half and looked dangerous each time they moved forward. Attackers Gaston Fernandez and Mauro Boselli were particularly lively.
In the second period the flow of the match changed, largely due to the fact that Veron had to leave the field injured.
The Uruguayans slowly crept into the game and could have drawn level had Gustavo Biscayzacu made the most of a clear goal-scoring opportunity.
Although Nacional had much of the ball, they didn't create too many problems for the Estudiantes defence.
Towards the end of the match, the Argentines pushed forward in large numbers and could have won by a bigger difference.
Had Mauro Boselli converted a clear-cut opportunity in the dying minutes, Estudiantes would have taken a better advantage into the second leg, which will be played at the Centenario stadium in Montevideo.
The vocal 40,000 capacity crowd were pleased with the final result, which means Estudiantes will progress to the final if they manage a draw in Uruguay.
Gregory Sica, Goal.com
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