A stirring second-half comeback kept alive USA's hopes of progressing into the last 16 – but they left Ellis Park bemused, confused and more than a touch angry after what looked like a perfectly good late winner was ruled out.

The team, having recovered from a two-goal half-time deficit, looked to have gone ahead four minutes from time when Maurice Edu poked home Landon Donovan's free-kick. However the Malian referee, Koman Coulibaly, spotted an infringement — although much to the frustration of the USA, he refused to explain what it was.

"I'm assuming it was a foul somewhere, it certainly wasn't offside," said Donovan, one of the players that crowded Coulibaly after the final whistle. "I just saw a normal free-kick and a goal. I don't know how much English he speaks but we asked him numerous times in a non-confrontational manner to explain his call but he just ignored us – or maybe he just didn't understand."

The USA coach, Bob Bradley, was also uncertain why the goal was disallowed. "One theory is that a Slovenia player had his arms around Michael [Bradley] and he tried to get loose and was called," he said. "But from what I've heard there were three fouls in the box, all from Slovenia players."

Still, USA will take enormous amount of pride from a performance that kept them in the competition. Slovenia were much the better team in the first half, and deservedly went in front when Valter Birsa drifted in from the right, turned and — spotting Tim Howard off his line – curled a left-footed 25-yard shot high into the net. Howard, who received a painkilling injection before the game, was beaten again just before half-time when Milivoje Novakovic's pass dissected the dawdling Oguchi Onyewu and Zlatan Ljubijankic coolly slotted home.

Bradley the coach responded by bringing on Edu and Benny Feilhaber at half-time – and immediately saw his team pull a goal back when Donovan seized on a mistake from Bojan Jokic, ran into the box and, from a tight angle, hit his shot hard at the Slovenia goalkeeper Samir Handanovic, who seemed to flinch as the shot missed his head and went into the roof of the net. "If there had been an option I would have rolled it across the goal but there wasn't so I decided to hit it hard," explained Donovan. "I don't think the keeper wanted to get hit."

That goal revitalised the large US support and the chants of "USA! USA!" were heard above above the wailing lament of the vuvuzelas. Led by the immense Jozy Altidore they continued to press and missed several chances to equalise before Michael Bradley levelled the scores in the 82nd minute. "We started the match poorly," said Donovan. "We were tentative. We sat too deep. At half-time we spoke about believing we can do it. My guess is that there's not many teams that could have done what we did in the second half."

"This team has shown it keeps fighting to the end," added Bradley. "It's a credit to the mentality of the players, that they are willing to fight for 90 minutes. There was one moment in the second half it seemed like one point gained, and another when it felt like two points lost."

The Slovenia coach Matjaz Kek, meanwhile, was happy with the result despite losing a two-goal lead. "We have gained a point today and we are in a really good position," he said. "I was expecting their comeback because they are physically very able, but I was hoping we would hold on."

Slovenia know they will probably need at least a point against England next Wednesday to qualify for the knockout stages. But for now Kek is not thinking about what lies ahead. "We have squandered a lot of energy, we need to recover and then we will talk about England," he said. "But it is clear what we are up against."

This is not a news report and may contain views expressed by the author which are not supported by GNM.