On 26 October 1988, Nacional won their third Copa Libertadores, beating Newell's Old Boys 3-0 in extra time of the final's second leg.
Nacional were a very experienced tournament side, having finished as runners-up in 1964, 1967, and 1969 before eventually lifting the cup in 1971, then again in 1980. Old Boys, on the other hand, were in the final for the first time after their title-winning season in the 1987-88 Argentinian Premier División.
Old Boys took the first leg, winning 1-0 at home on 19 October with a 60th-minute goal from forward Jorge Luis Gabrich. The teams then reconvened in Montevideo for the second leg, with a crowd of 75,000 gathering for the occasion.
The organizers instituted a new rule for the 1988 tournament; like the previous finals, it was determined on points, but whereas earlier tournaments went to a playoff when the teams were level on points after two legs, the 1988 edition went to extra time. At the end of extra time, the winner was decided by goal differential with a penalty shootout to follow if needed. As it turned out, it wasn't.
Nacional took a 2-0 lead into the break with goals from Ernesto Vargas (13') and Santiago Ostolaza (36'), then added a third from Hugo de León in the 78th minute to all but seal the win on goal differential, though the teams still needed to play through extra time. Tempers flared in the 115th minute, with the referee ejecting a player from each side as Nacional held on for the title.
Despite their history of success, Nacional have not returned to the final since. Old Boys reached it again in 1992, but lost to São Paulo.