Lewis Hamilton edged Sebastian Vettel to claim pole position for Sunday's Brazilian Grand Prix but both could face the stewards over incidents during qualifying.
In a very eventful session featuring occasional rain both drivers were involved in moments during Q2 that would probably be considered slam dunks for penalties.
Hamilton blocked Sergey Sirotkin approaching Juncao as he almost swerved into the side of the Williams driver, preventing him from setting a competitive time.
For Vettel, his infraction is more severe as, with rain looming, he was called to the weighbridge entering the pit-lane, in a hurry to return to his box, Seb drove onto the scales with the engine still running and then proceeded to drive away "destroying" the equipment according to the FIA, who also didn't get a representative measurement.
In the battle for pole, however, it was a 1m07.281s from the newly re-crowned world champion that gave him almost a tenth advantage over the Ferrari in second.
Their respective teammates followed in third and fourth with Valtteri Bottas 0.015s ahead of his fellow Finn Kimi Raikkonen.
The two Red Bulls rounded out the top six with just 0.002s splitting Max Verstappen and Daniel Ricciardo, the Australian will drop back to 11th following his five-place penalty after taking a new turbo.
Sauber benefitted from the weird weather and showed great pace to lead the midfield as Marcus Ericsson took seventh, Charles Leclerc's lap to make Q3 though was one of the performances of the session coming when it appeared the track was too wet for slicks.
Romain Grosjean followed in ninth for Haas with Pierre Gasly completing the top 10 in an impressive showing for the Honda-powered Toro Rosso.
Outside the top 10, it was the remarkable lap by Leclerc late in Q2 which knocked out Kevin Magnussen after all had appeared lost when the Monegasque felt heavier rain at Juncao.
The Dane will line up ahead of the two Force India's with Sergio Perez leading Esteban Ocon, the Frenchman will also drop down to 18th after his grid penalty for a gearbox change.
Renault would have a miserable day with Nico Hulkenberg only 14th and Carlos Sainz a casualty of a damp track at the end of Q1 in 16th.
Sirotkin was unable to set a representative time in Q2 after the aforementioned Hamilton incident and will start P15.
Brendon Hartley on his birthday would be 17th with Fernando Alonso and Stoffel Vandoorne 18th and 20th for McLaren and Lance Stroll in between for Williams.
Full result from qualifying can be seen below:
Monza plans big renovations for centenar
Ferrari much more of a unit compared to
Bottas: Worrying about Mercedes exit rum
Russell sets midfield goal for Williams
Brawn reveals agreement to help new engi
Ferrari confirm February launch date for
Perez talks up Stroll potential, plays d
18 Thoughts from F1 2018: Are Williams o
Ricciardo: Taking Renault 'to the next l
Norris wants to 'beat Sainz at every rac
Vettel has one problem with Kubica's F1
Pirelli has asked teams to simulate mand
McLaren 'very happy' with Renault, expec
Schumacher chooses Ferrari Academy over
Stroll matched Ocon in the simulator and
Wolff identifies race where he 'felt the
Sainz: McLaren aiming to lead the midfie
Marchionne death was a 'big loss' to Fer
Stewart hails Verstappen and arrival of
Kubica suggests Williams ignored initial
Bottas to contest Arctic Lapland Rally i
Vettel unsure if he'll enjoy same Ferrar
Alonso was 'never on the right team at t
Verstappen: F1 success 'a lot easier' fo
Mercedes had a pace advantage over Ferra
Ecclestone reveals Silverstone bid and f
Bianchi death & personal reasons re-shap
Hamilton had to be reigned in during sup
Norris believes McLaren more focused on
Grosjean: I have same desire to win as A
Verstappen only wanted to make Renault '
Kubica talks up F1 return: 'I know what
Wolff: Leclerc save at Spa vindicates Ha
Mexico GP future plunged into doubt by n
Wolff again raises prospect of future Sc
Sainz feels no pressure replacing Alonso
Hamilton just a 'chink in a chain' at Me
Raikkonen surprised by similarities betw
Renault reveal huge power deficit to eng
Verstappen still peeved by 'unfair' Monz
Hakkinen draws comparison to his early c
Mercedes' 2019 engine not yet hitting pr
Hulkenberg not so interested in comparis
Ecclestone warns against rise of street
Hartley hints Toro Rosso exit was politi
FIA concludes Halo did prevent Alonso's
Ricciardo: Process of making 2019 decisi
Brown: McLaren's 2018 a result of years
Giovinazzi expecting 'tough' start along
Pirelli: Tyres not only to blame for con
Vettel gets Di Montezemolo support: Schu
Ericsson tips - and hopes - Leclerc to '
Magnussen has 'almost forgot' what wins
Red Bull worried of help Ricciardo can g
Ericsson claims F1 is 'artificial' in co
Gasly will give Verstappen the 'hardest
Renault: 2019 potential depends on Red B
Russell wants to work with Kubica to pus
Racing Point will not be Force India's n
Hamilton expecting another title fight w
Ferrari admit possible benefits but want
Verstappen & Leclerc will be F1's new Ha
Schumacher's 2006 retirement left Ferrar
Sirotkin: 2019 Williams seat 'looked qui
Liberty 'trying' for Silverstone deal bu
Vettel would have been F1 champion with
Verstappen hints at 'Plan B' if Red Bull
Ricciardo denies money the cause for fai
Alonso leaving F1 akin to 'Real Madrid w
Gasly & Verstappen a 'good partnership'
Bottas rejects idea of seeking Rosberg a
Leclerc can be the 'incentive' Vettel ne
Todt suggests Verstappen becomes a stewa
Hamilton unscathed from minor crash duri
Perez admits Ocon relationship 'was neve
Red Bull's 2018 season could have been "
Alonso bemoans loss of engine noise in F
Ocon predicts busier 2019 as Mercedes re
Albon: Red Bull program was my only real
Bottas to approach 2019 'like I have not
Force India's new name & 2019 driver num
Force India officially confirm Lance Str
Mick Schumacher amazed by performance of
Norris keen to have 'valuable' Alonso ad
Schumacher 'as we all remember him' and
Ferrari claim the 'real Vettel' was back
Hamilton 'more relieved' after Mercedes
Verstappen admits bold Ocon moves in Abu
Force India rue costly races after faili
Bottas the 'only slight flaw' for Merced
Ricciardo 'confused' by Red Bull pace is
Williams: 'No one in the team' has doubt
Bottas & Vettel sense little difference
Brawn: 'Unacceptable' podium record for
Haas won't appeal decision of Abu Dhabi
Kvyat after Toro Rosso test return: It's
Leclerc savours 'special' first day as a
Sainz claims McLaren move a 'dream come
Rosberg: Ferrari lacked 'cohesion' after
Alonso adds Daytona 24 return to 2019 ra