Daniel Ricciardo has been disqualified from Singapore Grand Prix qualifying after stewards ruled his car's energy recovery system had deployed too much power.
The Australian Renault driver had qualified eighth on the grid on Saturday, one place ahead of teammate Nico Hulkenberg, but it emerged he had exceeded his power limit in the Q1 segment of qualifying.
Renault argued that the excess was very small and offered no measurable benefit but stewards said that was no defence under the rules.
Ricciardo is now likely to have to start from the pit lane on Sunday for a race where overtaking is difficult and track position a key factor.
His team later tweeted they will not appeal against the FIA stewards' decision.
Leclerc sets the pace in Singapore
Ferrari's Charles Leclerc has seized his third pole position in a row ahead of Sunday's Singapore Grand Prix.
The 21-year-old Leclerc, who started the last two races in Belgium and Italy from the front and went on to win both races, lit up the timing screens with a time of one minute, 36.217 seconds on Saturday.
Mercedes' world champion Lewis Hamilton was 0.191 seconds slower, with Monegasque Leclerc's Ferrari teammate Sebastian Vettel qualifying third after aborting his final lap and Red Bull's Max Verstappen fourth.
Ferrari, who have struggled around twisty circuits, had not been the favourites going into the weekend but Leclerc marked them out as contenders after setting the pace in the final practice session.
"We came here knowing that it would be a difficult track for us, but the team has done an amazing job to bring the package we needed," he added once out of the car," Leclerc said.
The race has been won from pole eight times out of 11 editions.
Hamilton, last year's race winner and the runaway championship leader with a 63-point advantage over team mate Valtteri Bottas, said he was happy to be on the front row.
Vettel, who came into the weekend eclipsed by Leclerc, appeared to have pulled out some of the old magic with provisional pole but pulled into the pits after errors on his final lap.
Saturday was the seventh successive time the four-times world champion, without a win for more than a year, had been outqualified by Leclerc.
Dutch 21-year-old Verstappen will still fancy his chances with Red Bull finishing second in Singapore for the last five years.
Bottas, who has never started the race in the top three, qualified fifth. Thai rookie Alexander Albon, in only his third start for Red Bull after moving up from Toro Rosso, lines up sixth in what is almost a home race.