Charles Leclerc topped the times, but team-mate Carlos Sainz crashed heavily as Ferrari out-performed rivals Mercedes in an incident-filled second practice session at the Abu Dhabi Grand Prix on Friday.
On a day of mixed fortunes for the 'scarlet scuderia' at the Yas Marina Circuit, the luckless Sainz - who also crashed out of opening practice at last weekend's Las Vegas Grand Prix after running over a loose drain cover - blamed a bump in the track.
"For some reason, there's been a change in the track over the years and there's two bumps - one at the exit of Turn Two and one at the entry of Turn Three -- that with this new generation of cars, it's very upsetting for the car," he said.
"It nearly caught me out in FP1. I had to change a few things in the set-up and in the line, but for some reason again it surprised me in that lap and the way I took the bump. I was just a passenger.
"With these cars, any small bump can really make you have a pretty heavy crash."
Sainz's car was less severely damaged than it was in Las Vegas the previous week and with Leclerc setting the pace in a truncated session, Ferrari ended the day looking likely to overhaul Mercedes in their battle for second place in this year's constructors' championship.
After another disappointing and inconsistent season, Mercedes are facing their first winless year since 2011.
Drivers George Russell and seven-time champion Lewis Hamilton ended the session - interrupted twice for red-flag stoppages - in sixth and ninth positions with Hamilton pessimistic about his and Mercedes' hopes.
Mercedes, on 392 points arrived in Abu Dhabi holding a four-point lead ahead of Ferrari, on 388, and will need to out-perform them to retain second place and an estimated additional 10 million euros ($109 million) in prize money.
- 'Tough battle' -
Leclerc topped the times by 0.043 seconds ahead of McLaren's Lando Norris, who is chasing the first win of his career, with three-time champion Max Verstappen of Red Bull third.
"It wasn't the greatest of days," said a downcast Hamilton. "We've had difficult qualifying sessions this year and getting out of Q1 and into Q2 has always been a tough battle.
"Getting into Q3 is a challenge. The work tomorrow is to try and get into Q3, but it's going to be close."
As a result of missing out on the opening session, when Mercedes gave his car to Danish junior driver Frederik Vesti, and then losing half of the second session to stoppages, Hamilton managed only four clocked laps.
Only minutes after the first re-start, following Sainz's crash, Nico Hulkenberg spun into the barriers in his Haas car. Like Sainz, he was unhurt, but another 10 minutes was lost, adding to the 23 minutes for the earlier accident.
Hamilton's day was not improved by continued speculation surrounding claims that his father Anthony had contacted Red Bull about a possible move next year and a later incident when Verstappen attempted to barge past him in the pit-lane exit tunnel.
In an impetuous move, he forced his car inside those of Russell and Hamilton who held position in the queue.
"They have to move," complained the Dutchman. "They're all driving slow and I want to go out because we're all limited on time and they just drive in the middle.
"When I tried to pass, they tried to squeeze me into the wall - so a bit silly!"
Verstappen, who is seeking a record-enhancing 19th win of the season and 54th of his career in Sunday's race, has won the last three Abu Dhabi events from pole position.