KAZAN - Belgium coach Roberto Martinez said he was the 'proudest man on earth' and lavished praise on his 'underdog' team for having the belief to upset five-times champions Brazil on Friday to reach the World Cup semi-finals for only the second time. A brave Belgium showcased their attacking brilliance then survived a spirited Brazilian fightback to claim a 2-1 win over the tournament favourites at Kazan Arena and reach the last four for the first time in 32 years. Martinez shook up his side by promoting Marouane Fellaini and Nacer Chadli to the starting line-up, while dropping Dries Mertens to allow playmaker Kevin De Bruyne to play further forward. The ploy proved a masterstroke as De Bruyne tied Brazil's defence in knots in a brilliant opening half, scoring a stunning 31st minute goal to double the lead after Fernandinho's own goal. 'Against them, there's a psychological barrier -- the yellow tops, the five world titles and everything that goes with that,' Martinez told reporters of facing Brazil. 'So we had to be brave tactically. It was a big gamble to change things and we needed the players to believe. 'Today was about their mentality, and I'm the proudest man on earth because I gave the players a very tough tactical assignment, and the way they believed until the last second was incredible.' Martinez's side will now take on France as they bid for Belgium's first World Cup final, having emulated Guy Thys's side who reached the last four at the 1986 tournament in Mexico. France were 2-0 winners over Uruguay earlier on Friday. Belgium needed to weather a fierce second half rally by Tite's side, who pegged one goal back with a header from substitute Renato Augusto but squandered a number of late chances for an equaliser. Goalkeeper Thibaut Courtois made a number of fine saves and needed every inch of his nearly-two metre frame to deny Brazil's talisman Neymar with a glove in the dying minutes. 'For me, Brazil are the best team in the tournament and without a doubt the biggest threat from open play,' said Martinez. 'We had to defend well for 90 minutes. But I felt our performance merited the opportunity to go through.' Anchored by a so-called 'golden generation' of players, Belgium only reached the quarter-finals after overcoming a huge scare against Japan. But they will now head into a semi-final against France with huge confidence after taking the scalp of Brazil. Man-of-the-match De Bruyne said his team had passed a 'test of character' in the closing 15 minutes as Brazil peppered the goal but were unable to find an equaliser. 'Now we face an extraordinary team in France, but any time you reach the semi-finals of a World Cup, you know you're not going to face weak opposition,' he said. 'We're on an equal footing with them, and we'll be doing everything we can to win.'