ST PETERSBURG, July 10 (Xinhua) -- Small details win big matches between good sides and so it proved on Tuesday night when Samuel Umtiti's 51st minute header gave France a 1-0 win over Belgium in the first World Cup semifinal.

Umtiti's goal means France will go to Moscow while Belgium will remain in St Petersburg to contest 3rd and 4th place on Saturday.

They said it would be a tactical game: a game of systems, but also individuals, such as Eden Hazard, Kevin de Bruyne and Kylian Mbappe, who can turn a game with their pace and touch.

France with their 4-2-3-1: with a strong backbone of Hugo Lloris, Raphael Varane, Umtiti, Ngolo Kante, Paul Pogba and Oliveir Giroud, allowing Mbappe and Antoine Griezmann room to roam and Blaise Matudi room on the left.

Belgium, flexible with three at the back, five in the middle and Kevin de Bruyne and Eden Hazard dropping back, picking the ball deep, running, cutting inside and continually probing, looking for the ball into Romelu Lukaku.

The game ebbed and flowed like the waters of the Baltic, just a stone's throw from the Saint Petersburg Stadium with Belgium dominating first, then France reacting before halftime.

De Bruyne and Hazard twice threatened at the start of the second half, before that moment Roberto Martinez warned about in his pre-game press conference happened: "You can't lose concentration against France."

But they did.

After 51 minutes Umtiti stole a yard on Marouane Fellaini from a corner and although it got a touch on the tall midfielder, his header ended up in the back on the net.

Giroud, always in the right place, but not always as clinical in his finishing had a chance to double the lead after Mbappe's backheel, but Courtois, for the second time in the game, made a vital stop

Dries Mertens came on, Lloris punched his first cross clear and Fellaini headed his second wide.

Belgium were pressing, but vulnerable on the break with both Hazard and Toby Alderweireld booked for stopping counterattacks and Axel Witsel also lucky to escape similar punishment.

Witsel stung Lloris's gloves from range, but the French keeper had a good view of it and the French were street smart enough to ensure Belgium didn't trouble him again, while Griezmann could have killed the game off completely in injury time.

So France and thousands of their supporters will be in Moscow on Sunday: the last time that many French were in the Russian capital was with Napoleon in 1812. That time it didn't end well, this time they will hope to truly conquer the city... and the World.