France flyhalf Romain Ntamack left the field with a suspected knee problem and Scotland winger Duhan van der Merwe also suffered an injury as the World Cup hosts won 30-27 in a warm-up match in Saint-Etienne on Saturday.Ntamack, 24, was helped off the field after 55 minutes, less than a month before the start of the World Cup after a collision with opposite number Finn Russell. READ | Boks get rousing airport farewell as daunting World Cup defence awaits Van der Merwe also suffered an issue and was helped from the pitch by a team doctor with a quarter of the game left.France fielded an almost full-strength team before the World Cup opener with three-time winners New Zealand on 8 September with Ntamack partnering captain Antoine Dupont at half-back.Scotland started the better at a sold-out and vocal Stade Geoffroy-Guichard, the 42,000-capacity ground which will host four games at the World Cup.The visitors led 10-6 after 22 minutes as Les Bleus' Thomas Ramos kicked two penalties in response to Kyle Steyn's try and Russell's shots at goal.Ramos kept his side in the game and they were 13-10 in front at the break as Dupont set up Ntamack to score after continued pressure.Their dominance continued after the break as winger Damian Penaud and flanker Charles Ollivon's tries took the score to 27-10.Ten minutes later, Ntamack was substituted after Russell charged into him, a worrying sight for coach Fabien Galthie who will announce his World Cup squad on 21 August. READ | England 'to wait and see' if red-card Farrell misses World Cup start Galthie said Ntamack suffered "a small hyper extension of the knee".After an hour of Saturday's game, France's advantage was cut to 27-15 as Van der Merwe strolled over in the corner following