Michael Bradley and Landon Donovan scored in the second half as the United States denied the Slovenes a win that would have made them the first team to advance to the knockout round.
“This team still understands how to fight for 90 minutes,” United States coach Bob Bradley said. “This is something we've seen time and time again.” Valter Birsa scored in the 13th minute and Zlatan Ljubijankic doubled the score for Slovenia in the 42nd.
The result at a cold and blustery Ellis Park left Group C wide open, with the last round of group stage matches to decide which teams move on.
Bradley scored the equalizer in the 82nd minute from Jozy Altidore's header. Altidore nudged it forward and Bradley, running at full speed, caught up to it just in front of the goal and tapped it up and over Slovenia goalkeeper Samir Handanovic's head for the equalizer.
United States substitute Maurice Edu volleyed Donovan's free kick into the net in the 86th but the goal was disallowed as the referee called an apparent foul on Edu.
“I still don't know why the goal was disallowed,” Bradley said. “Nobody knows at this moment.” Donovan gave the Americans hope at the start of the second half. Picking up a long pass from Steve Cherundolo, he broke in from the right flank and blasted a right-footer into the top of the net from a tight angle. It was Donovan's 43rd goal for the United States.
“I'm a little gutted to be honest,” Donovan said. “I don't know how they stole that last goal from us. ... I'm not sure what the call was. He (the referee) wouldn't tell us what the call was.” Going all the way back to 1930, the Americans have never won a World Cup match in which they trailed.
Birsa scored from 25 meters (yards), stunning United States goalkeeper Tim Howard, who stood frozen on the goal line and watched the shot drift into his upper left corner.
The Slovenian winger was left unchallenged by a passive American defense and had ample time to adjust his aim before curling the shot perfectly with his left foot.
Ljubijankic doubled the score on a counterattack, set up by attacking partner Milivoje Novakovic. Howard rushed out to stop him but Ljubijankic kept his cool and slotted the ball inside the far post.
The United States has two points in Group C after a 1-1 draw with England in the first match. The Slovenes have four points.
Samir Handanovic, Miso Brecko, Marko Suler, Bostjan Cesar, Robert Koren, Zlatan Ljubijankic (Nejc Pecnik, 74), Valter Birsa (Zlatko Dedic, 87; Andrej Komac, 90), Milivoje Novakovic, Bojan Jokic, Andraz Kirm, Aleksander Radosavljevic.
Tim Howard, Steve Chzerundolo, Jay DeMerit, Oguchi Onyewu (Herculez Gomez 80), Carlos Bocanegra, Clint Dempsey, Michael Bradley, Jose Torres (Benny Feilhaber, 46), Jozy Altidore, Robbie Findley (Maurice Edu, 46).
