Chelsea scored the go-ahead goal on Malo Gusto's 83rd-minute shot that went in after a pair of deflections, beating Palmeiras 2-1 for a spot in the Club World Cup semifinals.
Cole Palmer put Chelsea ahead in the 16th minute on Friday night but Estêvão, an 18-year-old who will transfer to Chelsea this summer, tied the score against his future club with an angled shot in the 53rd.
Gusto's shot following a short corner kick appeared to deflect off defender Agustin Giay and goalkeeper Weverton and sent the Chelsea portion of 65,782 fans into a frenzy. FIFA credited Weverton with an own goal.
Chelsea won't travel far for its next match, facing Fluminense on Tuesday at East Rutherford, New Jersey. Hércules came off the bench and scored in the 70th minute to lift Fluminense past Al Hilal 2-1 in Friday's earlier quarterfinal.
With Chelsea's win, three of the four semifinal teams will be from Europe, with one from Brazil.
The 23-year-old Palmer scored his first goal in the Club World Cup, and showed why he's widely considered one of the top attacking midfielders. He took a pass from Trevoh Chalobah and slipped the ball inside the far post.
Fans made it to Lincoln Financial Field on a holiday weekend that included a strike by nearly 10,000 city workers in Philadelphia, competition from an earlier Phillies game, and a concert and fireworks show near the Philadelphia Museum of Art. FIFA had slashed tickets to as low as $11.15.
FIFA president Gianni Infantino attended the game, the eighth of the tournament at the home of NFL Super Bowl champion Philadelphia Eagles.
There was a pregame tribute for Liverpool player Diogo Jota and his brother, André Silva, who were found dead near Zamora in northwestern Spain after the Lamborghini they were driving crashed and burst into flames on an isolated stretch of highway.
Key moments
Forward Liam Delap and defender Levi Colwill each got their second yellow cards of the tournament and will be suspended for the semifinal.
Takeaways
Estêvão agreed to a deal with Chelsea last summer that moved him to Chelsea after he turned 18.
