Japanese rider Takaaki Nakagami admitted he "couldn't cope with the pressure" after crashing out of the Teruel MotoGP on the first lap on Sunday.
The 28-year-old was the first Japanese in 16 years to start a grand prix from pole.
But his hopes of a first victory were over in a flash as he crashed out on his LCR-Honda at turn five on the opening lap at MotorLand Aragon.
He kneeled despairingly in the gravel with his head bowed before hitching a ride back to the pits.
"It was not what I expected, to end in the gravel," said Nakagami.
"I am very disappointed and sorry for the team because it was a great performance right from free practice.
"We were in the zone and I believed I could win but I felt a lot of pressure. I tried to avoid it but could not control it."
Nakagami said he pressed too hard as he tried to keep the chasing pack -- including eventual race winner Franco Morbidelli on a Yamaha -- at bay.
"I was too fast, there was a small mistake and I lost the front.
"It was difficult. Suddenly I was in the gravel."
Nakagami, who is seventh in the world championship with three races left, said he will learn from Sunday's errors ahead of the next round in Valencia in November.
"I want to keep going, to be strong. If I can improve then the future will be bright.
"But this is life and this is racing."