Argentina beat Belgium 4-2 to claim the Olympic title on Thursday and win their country's first Games medal in men's hockey, edging a close-fought match between two teams few expected to make the final.

Long playing in the shadow of a much-celebrated women's team, Argentina's men will leave Rio with their first Olympic hockey medal.

Belgium's sliver was their best finish at the Games in 96 years. They last took home bronze in Antwerp in 1920.

"We are a perfect team. Everybody knows their role everybody knows what they have to do on the field," said Argentine forward Facundo Callioni. "We just wanted the gold more than Belgium."

Both teams had beaten the odds in Rio to make their first Olympic final. Belgium eliminated world number two the Netherlands 3-1 on Tuesday, hours before Argentina routed defending champions Germany 5-2.

The Germans were reduced to scrapping it out for third place against the Dutch ahead of the main event, with twice gold medallists Germany claiming the bronze after winning a penalty shootout 4-3 following a tense 1-1 draw at full time.

Belgium's potent attacking game was evident from the start, building on a strong performance in the group stages where they racked up 21 goals, more than any other team in the tournament.With less than two minutes gone, Tanguy Cosyns deflected a strike from the top of circle to claim an early lead for the men in red. But the Argentine Lions roared back, scoring from two penalty corners and netting a third before halftime.

As storm clouds gathered, the intensity waned after the break, with neither team able to land a shot before Belgium's Gauthier Boccard put the ball into the bottom-left corner.

Belgium failed to score from two successive penalty corners deep in the fourth quarter. On the back foot, they swapped their goalkeeper for an extra man to chase a last-minute equaliser which never came.

"We had so many opportunities today, we should have done better," said Belgian captain John-John Dohmen. "If you don't score your opportunities you cannot win. It's simple."