The European champions showcased their class, overcoming a resilient MLS side with a blend of fortune and ruthless finishing to top Group B.
The French giants dominated early but needed a stroke of luck to break the deadlock in the 35th minute.
A wayward shot from Vitinha deflected off Khvicha Kvaratskhelia, wrong-footing Sounders goalkeeper Stefan Frei and nestling into the net. "It wasn't pretty, but goals count however they come," PSG coach Luis Enrique said post-match.
Frei had been in inspired form, notably denying Desire Doue with a stunning save to keep the score level earlier.
Seattle squandered a golden chance to stun PSG when Gianluigi Donnarumma's sloppy pass gifted Jesus Ferreira a clear sight of goal. The striker, however, fired wildly over from a tight angle. "We had our moment, but against teams like PSG, you can't miss those," Sounders coach Brian Schmetzer reflected.
The second half saw PSG tighten their grip, and their quality shone through in the 66th minute. A swift counter-attack, sparked by Doue's interception, saw substitute Bradley Barcola race down the left before squaring for Achraf Hakimi.
The Moroccan full-back smashed the ball past Frei to double the lead and secure PSG's place in the last 16, where they will face Group A runners-up Inter Miami. "We showed our mentality today," Hakimi said, as quoted on PSG's official X account.
Despite the defeat, Seattle battled valiantly, with Cristian Roldan nearly stealing a late consolation. His thunderous long-range effort in stoppage time sailed agonizingly wide, denying the 50,628-strong home crowd a moment to savor. "Our fans deserved something to cheer, but we gave everything," Roldan said.
PSG's victory, built on a stout defensive display that allowed no shots on target, sets them up for a blockbuster clash with Lionel Messi's Inter Miami.
Meanwhile, Seattle bow out of the tournament pointless but proud, having tested some of the world's best. "This experience will fuel us for MLS," Schmetzer added, looking ahead.
Paris Saint-Germain will attempt to move back to the Ligue 1 summit tonight when they host a resurgent Stade Rennais, with Luis Enrique urging his players to show a stronger response after last weekend's setback against Monaco.
Roberto De Zerbi has made it clear he plans to stay at Marseille and aims to turn the club into a contender for major trophies as they push through a crucial phase of the 2025 season.
Paris Saint-Germain are facing a worrying goalkeeping dilemma after Lucas Chevalier emerged as a major doubt for their Ligue 1 meeting with Rennes on Saturday.
Thomas Frank has insisted that Archie Gray and Lucas Bergvall are ready for Premier League starts after the pair impressed during Tottenham's 5-3 defeat to Paris Saint-Germain on Wednesday.
