BMW junior Joel Eriksson and McLaren-Honda protege Lando Norris have provisionally taken pole position for Sunday's two Formula 3 European Championship races at Monza.
The quickest time - and pole position for race two - changed three times in the closing two laps, but a raft of track-limits offences mean there will be a delay before the results are issued while stewards look into them.
Eriksson was sitting on top of the times in his Motopark Dallara-Volkswagen with a 1m43.790s, but that was subsequently deleted by stewards.
That appeared to leave the pole fight between the Carlin Dallara-VW of Norris and Prema Powerteam Dallara-Mercedes ace Callum Ilott, only for Mick Schumacher - running in tandem with team-mate Ilott - to jump to the top of the times with a minute remaining on 1m43.824s.
Norris then bettered that with a 1m43.786s, only for Eriksson to then take the chequered flag with a final lap of 1m43.720s.
Eriksson's earlier deleted time would have given him pole for race three - based on second-best laps - too, but instead that seems to be Norris's property at present, with Ilott second and Eriksson dropping to fifth.
"I was not out but they tell me I was out," said Eriksson of his disallowed lap.
"I clearly remember it, because it was a shit lap anyway.
"The session was really hard - there were 10 cars in a row all trying to get a slipstream, but in the end I got a really good position.
"I only had [Maximilian] Gunther in front - I had a little bit of a tow but the lap was really good as well."
Norris was fuming after spending much of the session mired behind a gaggle of Hitech GP and Van Amersfoort Racing cars.
"I did two push laps in the whole thing," he said.
"Whoever was leading didn't want to lead, and it was just dangerous if anything.
"On my first push lap some guy from Hitech bled off and literally came right in front of me, and then I dropped back by quite a lot.
"I had a tow but not much of a tow - I'd be four seconds behind at the start of the lap and having to overtake by the end of it."
Schumacher ended up third on the grid from Ilott, with Carlin team-mates Ferdinand Habsburg and Jake Dennis initially forming the third row for race two before Dennis was dumped to 12th when his best lap was discounted.
Prema pair Gunther and Guan Yu Zhou were next up, but Gunther had all but one hot lap disallowed, dropping him to ninth for race two and the back of the grid for race three.
Hitech's Nikita Mazepin is seventh with Carlin's race-one poleman Jehan Daruvala down in eighth and Ralf Aron (Hitech) rounding out the top 10 behind Gunther.
On the grid for race three, behind Norris and Ilott, are Zhou and Habsburg on the second row, Eriksson and Daruvala on the third, Mazepin and Aron on the fourth, then Harrison Newey (VAR) and Dennis completing the top 10, with Schumacher 11th.