Short before the kick-off of the second leg, Celtic's goal keeper Ronnie Simpson was hit by a projectile and had to be replaced by John Fallon for the last two legs. Celtic came in front via a penalty of Tommy Gemmell in the 21st minute. However Racing came back to win the match after goals from Norberto Raffo in the 33rd and Juan Carlos Cárdenas in the 48th minute. After the game, the Scottish dressing room was invaded by Argentinian fans and a battle between Argentinian and Uruguayan (who supported Celtic) fans broke out outside off the stadium.
Since the aggregate result was 2-2 after two legs, a third leg was needed to be played on a neutral field. The third leg was held in Montevideo, and is since known as "The Battle of Montevideo". The match started so brutal that the referee called both captains, and said that with the next foul committed by the Argentinian side, n° 6 (Alfio Basile) would be sent off, and that after the next foul committed by the Scottish side, n° 10 (Bobby Lennox) would get sent off. A couple of minutes later Basile was sent off. The next Celtic foul was however committed by John Clark. Keeping his word, Osorio sent off Bobby Lennox, however Celtic manager Jock Stein sent him back on the field saying Bobby Lennox did not commit any foul. Osorio sent Lennox off again several times as Stein did not allow Bobby Lennox to leave the field. Finally Bobby Lennox was escorted off the field by a policeman waving a sword. During the match a total of two Racing players (Alfio Basile and Juan Carlos Rulli) and four Celtic players (Bobby Lennox, Jimmy Johnstone, John Hughes, who kicked Racing's goalkeeper Agustín Mario Cejas twice, and Bertie Auld) were sent off. The last player to be sent off, Bertie Auld, refused to leave the field and stayed on all 90 minutes. When Auld refused to leave the field, amidst the total chaos on the field, Tommy Gemmell kicked one of the Racing players in his genitals, which went unnoticed by the referee. At one moment the Paraguayan referee completely lost control over the game and police needed to intervene. Racing won the game eventually via a goal from Juan Carlos Cárdenas in the 56th minute. Cárdenas defeated John Fallon with a 30 meter shot, after receiving an assist from Rulli. In total 30 fouls were given to Celtic and 21 to Racing. Most fouls however went unnoticed or were not called by the referee. As the Racing players wanted to do a lap of honor around the stadium, Uruguayan (Celtic) supporters showered them with anything they could throw. The Racing players had to wait in the center of the field, until the police had cleared the way to their dressing room.