Nani gave the Europeans the lead on five minutes, before Jermaine Jones and Clint Dempsey struck in the second half to give the US the lead. Yet substitute Silvestre Varela headed home in the final minute of stoppage time as the sides shared the spoils in Manaus.
Portugal headed into the encounter desperate for a win after their opening 4-0 loss to Germany, and were off to the perfect start after Miguel Veloso’s cross was poorly dealt with by American defender Geoff Cameron, whose miss-kick fell to the feet of Nani who smashed home from close range.
After going a goal down, the Stars and Stripes were eager to get back into the game as Fabian Johnson’s powerful left-footed strike was palmed out by Portuguese goalkeeper Beto.
Clint Dempsey was the clear danger man for the USA and was in the thick of the action in his side’s constant pressure on the Portuguese goal over the duration of the half, his well-taken free-kick sailing narrowly over the cross-bar before Beto produced a good save from his strong goal-bound effort minutes later.
The rest of America’s chances in the first period were reduced to long-range efforts as Portugal looked to break on the counter, and they almost doubled their lead as Nani forced a good save from Tim Howard from a Ronaldo cross following the Portuguese captain’s darting run down the left.
Howard was at his best just one minute before the half-time interval as Nani’s shot hit the post, yet Eder’s follow-up effort was superbly pushed wide by the sprawling American shot-stopper.
Portugal went into the break with the slender advantage, yet the United States were almost on level terms just 10 minutes into the second half as Michael Bradley saw his goal-bound shot cleared off the line after Tim Howard failed to close down Johnson’s cross for his well-positioned team mate.
The equaliser finally came for Jurgen Klinsmann’s men in the 64th minute after Jermain Jones latched onto a loose ball from a USA corner, hitting a sweet strike past the hapless Beto, who did not even move in the Portuguese goalposts.
Both sides then upped the tempo in the closing stages, yet it was the United States who took the lead with just ten minutes to go as Clint Dempsey was left unmarked in front of goal as he converted a Graham Zusi cross to send the vocal American supporters into ruptures.
Yet their dreams of a second consecutive win at this year’s Mundial were dashed in the last minute of stoppage time as Portuguese substitute Silvestre Varela headed home a pin-point Ronaldo cross in virtually the last play of the game as the match ended all square at 2-2.
The draw leaves Portugal rooted to the bottom of Group G alongside Ghana with just one point, while the United States move level with Germany on four points at the top.