Marine David Tait alleged Sergeant David Foggin punched him through an open tent window after he was ordered to stand up during the lecture.
The soldier gave evidence in the trial of two Royal Marines non-commissioned officers accused of bullying recruits. A lieutenant is also accused of failing to report the matter.
The court heard how the alleged attack happened while Marine Tait was taking part in the tough 30-week Royal Marines commando training course. Marine Tait was one of 40 recruits on Exercise First Base at Woodbury Common, near the Marine's base in Lympstone, Devon, in 1996.
Marine Tait said: "I was instructed to stand up by Corporal Amphlett, who was giving the lecture, because I was falling asleep. I felt a strike to the right hand side of my face.
"I didn't turn around, but I heard Sergeant Foggin's voice instructing me to wake up. I didn't report it to anybody because I thought it was trivial."
The court has heard how other recruits were allegedly punched and kicked in a string of attacks by Sergeant Foggin and Corporal Amphlett.
The allegations were later brought to the attention of Lieutenant Michael Geldard but he failed to take action.
Sgt Foggin denies four charges of ill-treating recruits and four alternatives of battery. Corporal Amphlett denies one charge of ill-treating recruits and an alternative charge of battery, while Lieutenant Geldard denies one charge of conduct to the prejudice of good order or military discipline.
The case continues on Monday.Reuse content