Montenegro put an early end to the medal bid of water polo powerhouse Hungary on Tuesday, clinching a spot in the semi-finals in a thrilling penalty shootout.

Also advancing were world champions Serbia, who overpowered Spain 10-7.

Hungary's men's team, the most successful in the sport's 116-year Olympic history, had arrived in Rio de Janeiro seeking to put things right after failing to reach the podium at the 2012 London Games.

The Hungarians, who have won gold nine times in previous Games, managed to battle back from an 5-3 deficit at halftime, levelling the score at 9-9 late in the fourth quarter.

In the decisive penalty shootout, however, Montenegro got the upper hand. Their goalkeeper Milos Scepanovic, 33, had shown lightning-fast reflexes to make dazzling blocks throughout the game and saved two shots in the shootout, which ended 4-2 in Montenegro's favour.