Remy, who signed for the Blues for £10.5million from QPR last weekend, came off the bench in the 58th minute of Thursday's encounter between the Euro 2016 hosts and the reigning European champions at the Stade de France and was on target a quarter of an hour later.
The 27-year-old blasted home a left-footed shot from inside the area past David De Gea after excellent build-up play involving Mathieu Valbuena, Moussa Sissoko and Karim Benzema.
Earlier in the second half, Benzema thought he had opened the scoring from Sissoko's pass but was frustrated to see the assistant referee had raised his flag for offside.
Remy's new club team-mates Diego Costa and Cesc Fabregas endured a frustrating evening and were withdrawn midway through the second half.
Ten minutes after Remy's goal, substitute David Silva slid a shot just wide of Hugo Lloris' far post but that was as close as the visitors came to an equaliser.
Spain open their European qualifying Group C campaign against Macedonia in Valencia on Monday night, while France are back in friendly action on Sunday when they take on Serbia in Belgrade.
The match heralded something of a new dawn for Vicente del Bosque's side, who crashed out in the group stages at the World Cup in the summer following defeats to Holland and Chile.
Some changes were enforced - David Villa, Xavi Hernandez and Xabi Alonso have all retired from international football, while Gerard Pique and Andres Iniesta were unavailable due to injury.
There was also a conscious effort to introduce fresh blood as De Gea started in goal, Daniel Carvajal and Mikel San Jose came into the defence and Koke was handed a start in midfield.
It was France, however, who dominated the opening exchanges and Benzema was close to giving the hosts the lead when he found space inside the area but the striker's low shot was denied by De Gea.
Spain's renowned ability to keep possession was failing them too often, as the visitors struggled to handle their opponents' aggressive pressing.
Despite their strong start, however, France were unable to find the goal they deserved as Benzema was again guilty of wastefulness, this time failing to connect with Paul Pogba's chipped ball into the area.
Spain's evolution from a possession-based style of play seems centred on a willingness to pass forwards earlier but Costa was too often isolated up front.
Benzema unleashed a bending shot from the edge of the area in the 38th minute but his effort flew straight into the hands of De Gea.
The visitors enjoyed their best spell towards the end of the first period but Lloris remained untested in a goalless first half.
France thought they had broken the deadlock when Benzema steered in Sissoko's cross shortly after the restart.
The goal, however, was ruled out after the linesman flagged for offside, despite Benzema appearing to be behind Sissoko when the ball was played.
Both sides made changes as the second period went on and some of the contest's momentum was subsequently lost.
France continued to look the more threatening, however, and in the 73rd minute, the home side finally found the net as Sissoko's neat flick put through Valbuena, whose cut-back was swept home by substitute Remy.
The visitors pressed and probed in the latter stages, with Silva particularly influential off the bench.
Isco was brought down in the area in the the dying moments but the referee waved away Spain's penalty appeals to ensure France held on for a morale-boosting win.
Watch Spain's European Qualifier at home to Macedonia live on Sky Sports 5 HD on Monday night, with coverage underway from 7pm.