Seattle skipper Lodeiro completed a remarkable fightback in the ninth minute of stoppage time, burying his second spotkick of the game to give the Sounders an improbable draw at Mexico City's Estadio Olimpico Universitario.
Uruguay international Lodeiro had handed Seattle a lifeline in the 77th minute after slotting the Sounders' first penalty. Until that point Pumas had looked to be cruising to victory after two goals from Argentine striker Juan Dinenno left the Mexican club in control of the tie. But the game swung back in Seattle's favour after two interventions from VAR resulted in Sounders penalties.
The first came 13 minutes from time when VAR ruled Pumas substitute Sebastian Saucedo handled in the area. VAR then prompted referee Ivan Barton to award a second Seattle penalty deep into stoppage time after Cristian Roldan was adjudged to have been fouled in the box. The extraordinary conclusion means Seattle's hopes of becoming the first team from Major League Soccer to be crowned champions of North America, Central America and the Caribbean since 2000 are very much alive.
Seattle coach Brian Schmetzer admitted however that his team had been below par. "It might take me until we're halfway back home to really understand what happened in the game," Schmetzer said. "It certainly was an interesting game. "I think it's just getting back to our team understanding what we're good at because tonight I don't think we were at our best."
Seattle host Pumas in the return leg next Tuesday. For long periods on Wednesday, Seattle looked dead and buried as Pumas took a 2-0 lead. Dinenno rifled home a controversial first-half penalty before burying a header early in the second half to put the Mexican club ahead. A lacklustre first half burst into life just after the half-hour mark when Pumas striker Dinenno was brought crashing down in the area after a rugged joint challenge from Yeimar Gomez Andrade and Xavier Arreaga.
Barton pointed to the spot and despite furious protests from Seattle players there was no intervention from VAR to overturn the decision. It looked as if Sounders goalkeeper Stefan Frei had rescued Seattle after brilliantly palming Dinenno's penalty over the bar. But VAR ruled rightly that the Seattle goalkeeper had stepped off his line just before the penalty and Barton ordered the kick to be taken again. This time Dinenno made no mistake, firing into the opposite corner as Frei dived the other way to make it 1-0.
While Dinenno's first goal had been shrouded in controversy, there was no doubt about his second in the 48th minute.
A superb curling cross from substitute Jesus Rivas split the Seattle defence and Dinenno timed his jump to send a thumping header flying past Frei into the top corner, his ninth goal of this season's Champions League. Seattle had a golden chance to pull a goal back on 51 minutes when Roldan's low cross left Raul Ruidiaz with a simple finish from close range. But the Peruvian striker's shot was too low and Pumas keeper Alfredo Talavera saved brilliantly for a corner.