Young Monegasque driver Charles Leclerc surprised many by putting his Sauber into the final top 10 shoot out How does it feel to drive an F1 auto at Paul Ricard?
Vandoorne, who ended up 19th in a "learning" session, had also been a spinner as he searched for the limits of the track.
A wheel then came off Sergio Perez's Force India vehicle at speed on the Mistral straight in the late afternoon.
Vettel took his one-point lead two weeks ago when he won the Canadian GP.
Charles Leclerc twice spun to a brief stop, while Max Verstappen drove his Red Bull wide on consecutive corners and Kevin Magnussen had a near miss with Sergio Perez. It's such a attractive place. It makes our preparations trickier than usual, but that element of the unknown adds to the challenge.
Finnish team mate Valtteri Bottas, who had gone top moments earlier, had to settle for second - just 0.118 of a second slower - as the Silver Arrows locked out the front row in style.
Brazil ease past Serbia, set up Mexico clash in last 16
Serbia need a win or combination of a draw plus a multi-goal loss from Switzerland to make it to the knockout rounds. Anxious no more, Brazil is through at the World Cup . "I'm apparently at peace", the Brazil coach said.
The morning session ended with a scare for Sauber's Marcus Ericsson after his auto burst into flames when he spun out of control and slammed into a barrier.
The Swede worryingly remained in the auto before marshals arrived with an extinguisher and he clambered out from underneath the halo head-protection system. Hamilton was fastest in both sessions on Friday. Let's see if we can start from there tomorrow.
Defending four-time champion Lewis Hamilton of Mercedes, who trails Vettel by a single point, was 12th, but did not attempt to clock a meaningful lap time.
"The long-runs felt pretty OK, quite consistent", said Vettel. "Every time, I was driving around at home last week the games were on everywhere".
"After Saturdays, I'm always here answering negative questions", Alonso, whose future at McLaren remains uncertain, told Sky Sports.