Favourable road position for the Haradh - Shubaytah stage meant Alonso was primed to contend for a maiden stage win, having finished second to the Century buggy of Mathieu Serradori two days prior.
But his hopes were dashed just over a kilometre into the test when his Hilux was sent into a double rollover going over a dune and sustained damage that forced a subsequent stop.
Alonso wound up losing over an hour in the weather-shortened stage, and would now need to make up a similar gap to the four cars ahead of him in the general classification over the two remaining stages if he is to recover a top-10 finish,
"I'm fine," Alonso said after the crash. "As soon as we started, we had the roll - but other than that it was a good day, we're here.
"We didn't lose much, just some places, and I don't mind if I'm sixth or 13th either way.
"I'm so lucky to still be in the Dakar, to stay in this tough race. We don't give up, and we didn't come here to ride around.
"I'm trying to win stages and that's what we like to do. Today I wanted to win. You can fail, but you can't not try."
#310 Toyota Gazoo Racing: Fernando Alonso