River Plate, one of Argentina's most famous clubs, faces a two-game playoff to stay in the first division following a 2-1 loss against Lanus on Saturday.
River Plate is confronted with the real possibility of being relegated to the second division for the first time in its illustrious history.
The Buenos Aires club has won the first-division 33 times, 10 more than No. 2 Boca Juniors, and plays in Monumental Stadium, probably the best venue in the country.
Five matches were played simultaneously on Saturday in the final round of the Clausura, all involving clubs in the relegation fight.
River Plate goes against second-division team Belgrano with the winner over two legs staying up.
Facing a playoff of this kind is humiliating for River, a club known as the ''Millionaires.'' Recently it has become better known for debts reported at $19 million, which has forced it to sell top talent to European clubs to stay afloat.
In other results, Olimpo defeated Quilmes 1-0, Argentinos Juniors and Tigre drew 1-1, Independiente defeated Huracan 5-1 and Boca Juniors rallied to draw Gimnasia 2-2.
It was the final match for Boca Juniors 37-year-old striker Martin Palermo, who retires as the club's all-time scoring leader with 236. He did not score on Saturday. In addition to his goals at Boca, Palermo scored 36 for Argentine club Estudiantes, 25 for Spanish clubs Villarreal, Betis and Alaves - and 9 for Argentina.
The results mean Olimpo and Tigre will stay up next season and do not face a playoff.
Quilmes is demoted automatically.
Huracan and Gimnasia face each other in a one-off match with the loser dropping automatically to the second division. The winner will join River Plate in a two-game playoff against second-division opposition. That opponent will be Union or San Martin of San Juan.
Relegation in Argentina is determined on results over three years, not a single season.
Godoy Cruz defeated All Boys 1-0 in a late match on Saturday.
The Clausura ends on Sunday with four matches.
Velez Sarsfield, which won the title last weekend, faces Racing, Arsenal is against Estudiantes, Newell's faces Colon and Banfield plays San Lorenzo.
