In the 19th minute, Lucas Albertengo looked to be chasing a lost cause as Lux stormed out of his area seemingly ready to make a simple clearance.
Somehow, though, the 35-year-old made the fatal error of misjudging the flight of the ball and caught it instead... about 10 yards outside his box.
Naturally, Lux's calamitous loss of focus meant the former Deportivo goalkeeper was immediately sent off and forced River Plate to play with 10 men for over 70 minutes.
Independiente finally broke the deadlock in the 82nd minute as Nicolas Domingo condemned los Millonarios to a 1-0 defeat.
See also...
Tony Pulis's son Anthony hired as Saint Louis coach on same day his dad is sacked
Feuding Flamengo team-mates square up; one of them scores, immediately flips bird at the other
Chelsea loanee Fankaty Dabo lobs his own goalkeeper from 40 yards out for Vitesse Arnhem
