Chuck Aoki's foul with 30 seconds to go sent Canada through to the final as they beat the Beijing gold medallists 50-49 in their semi-final at the Basketball Arena.
Canada took advantage of the USA's slow-starter reputation and began the game with Zak Madell and Mike Whitehead to add some speed and power.
They got off to a blistering start as Madell, sandwiched between two Whitehead goals, put USA on the back foot within three minutes. They kept piling on the pressure and had a lead of 16-9 at the end of the first quarter.
USA started to turn the screw in the second quarter, with Aoki the instigator as he scored four goals and forced Canada out of bounds. While Canada's line-up was standing up well to the USA, their opponents were clearly a threat as the midway point was reached at 28-23 to Canada.
Aoki got USA's first turnover of the second half but Canada soon got the ball back as Whitehead pushed Derrick Helton out of bounds. Canada's possession was short-lived as Helton got the ball back and converted the score.
The USA forced Dave Willsie and Madell into making fouls, bringing it back to a one-point game in Canada's favour.
But an illegal use of hands by Seth McBride on Garett Hickling gave Canada a point back and Aoki fouled in the last 15 seconds of the period, giving Canada a 3-point lead going into the final quarter.
After a flurry of action, the USA had two time-outs left to get them out of trouble, and it looked like they would at least force the game into overtime as it was tied at 49-49.
But Aoki went from hero to zero in the final 33 seconds as he fouled Madell to give Canada a vital turnover. Hickling took his time to convert the goal, leaving no time for USA to take it to overtime and Canada won 50-49.
In the other semi-final, Australia showed no sign of weakening as another dominant display saw them beat Japan 59-45.
An offensive foul from Shin Nakazato gave them an early advantage and Chris Bond came on from the bench, scoring two goals and winning a turnover within the first minute. Australia were three points in front at the end of the first period.
Australia put both 3.5 players Ryley Batt and Bond on the floor in the second quarter and soon looked to be taking a stranglehold on the game. But they got carried away with their hitting, with both Bond and Josh Hose paying a visit to the sin bin. Australia still took a 29-23 lead into half-time.
Bond forced yet another turnover in the third quarter to go seven goals ahead, as did Greg Smith soon after to raise it to eight. Daisuke Ikezaki also spent some time in the sin bin, but responded with an end-to-end push, showing his speed to cruise past Australia's defence and score.
Australia stretched their lead further and the teams went into the final quarter with the score at 44-33. Japan had several attempts at pulling the score back in the fourth period, with Ikezaki's speed and ball distribution working well to score goals on their ball.
They reduced the deficit to nine goals, but it was too little, too late, and Australia secured their place in the final, eventually stretching their lead to 14 points.