Brazil cruised to a 4-0 win over Mexico in the quarter-final of the Copa America football tournament on Sunday after being set on their way with a hugely controversial penalty.

Alex scored from the spot amid furious Mexican protests in the 28th minute after goalkeeper Oswaldo Sanchez was judged to have upended Adriano.

Adriano, a constant torment to the Mexican defence, added two more himself in the second half to make him the competition's top scorer with five goals. Substitute Ricardo Oliveira added the fourth.

The match had been evenly-balanced until the penalty incident.

Adriano broke clear and shot, Sanchez saved, the two chased after the rebound and the Brazilian's legs crumpled.

Television replays showed that Sanchez did not touch Adriano but referee Oscar Ruiz pointed straight to the spot and Alex converted to a deafening chorus of jeers from the Peruvian crowd.

Coincidentally, it was Ruiz who awarded three penalties to Brazil in last month's World Cup qualifier against Argentina. All were given for fouls on Ronaldo, who converted all the penalties himself.

Adriano gave the Mexican defence a torrid time throughout the first half.

He had a header pushed onto the crossbar by Sanchez in the third minute and was close again 15 minutes later when he headed over at the far post from Kleberson's cross.

The goal sparked Mexico into life and they twice came close to equalising. Hector Altamirano had their best effort when he rifled in a 30-metre free kick which Julio Cesar parried to Octavio Valdez, who fired the rebound over.

Altamirano and Pavel Pardo were close with other free kicks while Duilio Davino forced another save from Julio Cesar with a close-range header.

Mexico continued to push forward after the break and nearly equalised when Adolfo Bautista's close range header was brilliantly saved by Julio Cesar.

But Brazil looked menacing on the break, with Luis Fabiano and Kleberson both wasting good chances.

They settled the game in the 66th minute when Adriano received the ball on the edge of the area, nobody closed him down and he scored with a low, left-foot shot into the far corner.

Thirteen minutes later, he added the third after pouncing on a mistake by Sanchez, rounding the goalkeeper and scoring in the empty net. He also set up the fourth for Ricardo Oliveira with three minutes to go.