Johann Zarco admits he was unaware Dani Pedrosa had crashed after he was nudged wide by the Tech3 rider at Turn 13 on the opening lap.
Zarco slotted into fourth at the start behind Pramac's Jack Miller and the Honda duo of Marc Marquez and Pedrosa.
The French rider felt he had the pace to run with the leaders, but was worried he would get held up behind a “safe” Pedrosa and lunged up the inside of him at Turn 13.
Zarco held the tighter dry line on the inside of the corner, but had to run wide and forced Pedrosa further off line as well, with the Honda man suffering a highside as he accelerated on a damp patch.
“I saw Marc and Jack leading the race, and we had a better pace than Dani,” Zarco, who finished second in the end, explained.
“Dani, knowing him, he can sometimes be safe at the beginning of the race and, I don't want to miss the rhythm from the two guys in front.
“So, I took quickly the decision to overtake him in the corner 13, where it was like the race line plus inside another dry line, and I used this dry line to overtake.
“But, when you are going into the corner with this different line you have to go a little wide.
“Problem is, going this line is getting a little wet and I had to pick up a lot the bike to not crash, because if I crash I push him away and he [would] crash.
“I did not crash but I didn't know he'd crashed. I saw Alex [Rins] overtake me and for me Dani was still behind. So he has been unlucky on the wet patches.”
Pedrosa will have to undergo check-ups in Barcelona this week after pain in his right wrist developed after the crash.
“There's not much to say about the race,” he said.
“I think we did a great job this weekend, and I was riding very well. My race ended before I finished the first lap.
“Race Direction needs to look at every rider's safety. Right now I have a lot of pain in my right wrist. I'll have it checked again in Barcelona on Tuesday.”