A young Arsenal team ran out comfortable 5-0 winners over Nottingham Forest at The Emirates, with debutant Martinelli and the returning Rob Holding on the scoresheet.
Reiss Nelson’s free-kick flew just wide of the target early on before Shkodran Mustafi flicked a corner over the bar from close range.
Nelson had another chance to open the scoring before 18-year-old Gabriel Martinelli broke the deadlock on his first start for The Gunners.
Callum Chambers volleyed a superb first time cross into the box for Martinelli guide the ball into the top corner with his head.
Rob Holding doubled Arsenal’s lead with a header on his return to the first team before Joe Willock made it 3-0 with ten minutes to go.
Reiss Nelson deservedly got on the scoresheet to make it four before Martinelli wrapped up the scoring with his second.
The gloss was taken off the Arsenal victory slightly as Emile Smith-Rowe was stretchered from the field as he came off worse in an aerial challenge.