International Friendly: France 1 Spain 0
Remy moved across London from QPR last Sunday and celebrated the move by coming off the bench to clinically secure a friendly victory for his national side.
The 27-year-old's path to Jose Mourinho's first team is likely to be blocked by Diego Costa, who has enjoyed a prolific start to life in the Premier League - quite at odds with his tough baptism on the international stage.
Costa made it five goalless appearances for Spain, largely isolated and starved of service as Vicente del Bosque's team made a tentative start to their new era.
Spain's dismal World Cup defence in Brazil was followed by three stalwarts of their golden era - Xavi, Xabi Alonso and David Villa - retiring from international football.
Del Bosque also sent out a side with one eye apparently on Monday's opening Euro 2016 qualifier against Macedonia and his men lacked cohesion throughout.
It was left to France to provide the game's eye-catching moments, with the impressive Karim Benzema wrongly having an effort chalked off for offside before Remy settled matters.
Dani Carvajal was one of three debutants in the Spain line-up and the right-back was alert to scramble the ball away from Antoine Griezmann after Moussa Sissoko enjoyed an early burst down the visitors' left.
David de Gea was kept busy, first denying Benzema after he was played onside by Real Madrid team-mate Ramos before comfortably saving from Paul Pogba.
Pogba looked on as Benzema failed to make clean contact with his wonderfully judged 25th-minute ball into the box, while a deflected drive from Cesc Fabregas that looped gently over Hugo Lloris' crossbar was the closest Spain came in the opening half.
Benzema connected cleanly to send a rasping 20-yard effort goalwards six minutes before half-time but De Gea was equal to the task once more.
France thought they have the lead in the 50th minute when Benzema crowned a crisp team move with an impudent flick, only to be adjudged offside. Replays suggested the striker was level with the ball as Sissoko provided a low cross.
Raul Garcia's debut ended after an hour with David Silva's introduction and the Manchester City playmaker finally lent a touch of cohesion to Spain's attacks, although Mathieu Valbuena's shot past the near post in the 64th minute was a clearer opening than anything the visitors had enjoyed.
The winning goal arrived in pleasing fashion with 17 minutes remaining. France's build-up play was incisive once more and Valbuena darted onto Sissoko's clever flick to unselfishly cut back for Remy to rifle past De Gea.
Silva glided beyond a challenge to shoot narrowly past the far post with seven minutes to play - a fleeting reminder of the mesmerising style Spain must rediscover as they rebuild.
However, Benzema capitalising on slack late defending to draw a sharp stop from De Gea perhaps demonstrated how much work must be done.