Ferrari's Charles Leclerc was fastest in the second practice at the Las Vegas Grand Prix at the end of an embarrassing first night on Thursday when the opening session was abandoned after just nine minutes because of a loose drain cover.
Leclerc was 0.517 seconds faster than his team-mate Carlos Sainz, who had been at the centre of the farcical FP1 session when his car hit the drain cover earlier.
Adding to the messy nature of the opening night of action at the new track, the second practice finished at 4am local time having started two and a half hours behind schedule and with fans being asked to leave the venue.
Sainz was forced to a stop in his Ferrari after hitting the cover, resulting in a red flag and damage to the front of his car on what should have been a triumphant return for F1 to Vegas after two races in 1981 and 1982.
Sparks flew from the bottom of Sainz's car after it hit what organisers called a "water valve cover".
After some delay organisers announced that the session would not be resumed.
The second practice session was scheduled for midnight local time but was delayed as course workers carried out urgent checks and repairs.
Adding to the public relations damage, fans at the track were left unclear about when that session would take place for over two hours before they were asked to leave by police with volunteers and staff having reached the end of their shifts.
When FP2 began, Sainz was promptly handed a ten-place grid penalty for the weekend's race for using a third energy store of the season — one more than regulations allow. Stewards said they had no choice but to impose the mandatory sanction despite "highly unusual external circumstances".
Ferrari team principal Frederic Vasseur was clearly angry about the state of the track in a news conference after FP1.
"We damaged completely the monocoque, the engine, the battery. I think it's just unacceptable," he said.
"It cost us a fortune. I think it's just unacceptable for F1 today," he added.
'How can you even dare?'
In a heated press conference, Mercedes team chief Toto Wolff reacted with fury to a question from a reporter about whether the incident was a "black eye" for the sport's organizers.
"That is not a black eye, this is nothing. We are on Thursday night, we have a FP1 that we are not doing, they are going to seal the rain covers and nobody is going to talk about that anymore tomorrow morning," said the German.
"It's completely ridiculous. How can you even dare trying to talk bad about an event that sets new standards in everything? You are talking about a drain cover that has been undone, that has happened before and is nothing," he said.
"Between the FIA and the track, everybody needs to analyze how we can make sure this doesn't happen again, but talking about a black eye for the sport on a Thursday evening, nobody watches that in European time anyway," he added.
Esteban Ocon's Alpine also suffered damage and the team were forced to begin changing the chassis on his car.
A similar incident occurred at the 2019 Azerbaijan Grand Prix when George Russell, then racing for Williams, had his car hit by a loose manhole cover and the first practice session was canceled.
Thursday's practice was the first time the new circuit had been raced upon.
While the Ferrari pair were out front, Aston Martin's Spanish veteran Fernando Alonso was third fastest ahead of Red Bull's Sergio Perez.
Alfa Romeo's Valtteri Bottas was fifth quickest with world champion Max Vertstappen of Red Bull sixth, 0.918 behind Leclerc.