Stylish Argentina strolled into the men's football final courtesy of a 3-0 win over Italy at Karaiskaki Stadium.
Boca Juniors' Carlos Tevez scored his seventh goal in five matches to give Argentina the lead on 15 minutes.
Luis Gonzalez doubled the lead in the 69th minute and namesake Mariano made it three six minutes from time.
The South Americans, who have now scored 16 goals without reply in their five matches, will play Paraguay in Saturday's final.
After an early scare when Italy striker Alberto Gilardino broke clear only to send a weak shot straight at keeper German Lux, Argentina always looked in control.
New Manchester United signing Gabriel Heinze went close from a corner for Argentina but his header drifted just past the post.
Mauro Rosales provided the cross for Argentina's opener but Tevez actually latched onto a poor clearance from Italy defender Matteo Ferrari to fire home.
Andres D'Alessandro went close to a second for Argentina but Italy keeper Ivan Pelizzoli made a good save on 35 minutes.
Two minutes later Tevez thought he had scored his second of the match only for the strike to be disallowed for offside.
It took until the 69th minute for Argentina to make their class tell when Tevez linked up with Gonzalez who launched an unstoppable shot past Pelizzoli.
And six minutes from time Tevez crossed for substitute Gonzalez to tap in.
Italy coach Claudio Gentile admitted Argentina, who had played almost the entire team in the recent Copa America, had too much for his team.
"There were definitely superior to us," said Gentile.
"The Argentine squad has about eight full internationals and most of them were in (the Copa America in) Peru and that really is quite significant.
"We paid the price for making too many mistakes, but it was an honourable defeat and we can hold our heads high."
But Argentina coach Marcelo Bielsa said his side had to work hard for the emphatic win.
"It may look easy to people watching, but we feel no game is ever easy," said Bielsa.
"Our enthusiasm is tempered by the fact we haven't won anything yet."
Argentina, who have not won an Olympics gold medal since 1952, will meet the winner of the second semi-final between Iraq and Paraguay.