The West Ham attacker scored a late stunner to earn the three points after Bogdan Stancu’s second-half penalty had cancelled out Giroud’s opener.
Olivier Giroud and Dimitri Payet were the heroes for Didier Deschamps’ men as they fired their side to victory.
After an underwhelming first half from the tournament hosts, it was Giroud who got things underway.
The striker opened the scoring just before the hour mark, with Dimitri Payet the creator, crossing in for the Arsenal man to head home.
However, Patrice Evra gave away a penalty seven minutes later when Patrice Evra tripped up Nicolae Stanciu in the box and Bogdan Stancu was on hand to convert.
And Payet saved Les Bleus’ blushes late on as he sent a stunning strike into the top corner from the edge of the box, securing the three points.