In a thrilling qualifying session for the Formula 1 Mexican Grand Prix, Charles Leclerc of Ferrari clinched pole position, leading a surprising Ferrari 1-2 alongside teammate Carlos Sainz. The duo outpaced the formidable Max Verstappen of Red Bull Racing, who will face a post-session stewards' investigation along with several other drivers.

Verstappen, who had been dominant in practice sessions leading up to qualifying, could not match the pace of the Ferrari pair. On their first runs in Q3, Leclerc and Sainz found extra speed as the track temperature dropped slightly. Leclerc's impressive lap time of 1m17.166s secured him the pole position, with Sainz just behind by a margin of 0.067s. Verstappen trailed in third place, 0.120s behind Leclerc.

The excitement intensified during the second runs in Q3 when Leclerc and Sainz failed to improve their lap times. This gave Verstappen an opportunity to snatch pole position, as he set personal bests in the first and second sectors. However, despite his impressive effort, Verstappen fell short by 0.097s, ending up in third place.

Meanwhile, Daniel Ricciardo of AlphaTauri made his presence felt by securing a sensational fourth place, edging out Sergio Perez. Lewis Hamilton, however, could not replicate his Q2-leading form and settled for sixth place as the leading Mercedes driver.

The qualifying session was not without its controversies. Verstappen faces an investigation for an incident of impeding in Q1, alongside George Russell. Additionally, Lewis Hamilton is being investigated for exceeding the speed limit under yellow flag conditions.

In Q2, Hamilton's late run put him in first place, with Verstappen still in the pits and easily securing a place in the final segment. However, Alexander Albon's late improvement was nullified when his time was deleted due to a track limits violation. Albon finished ahead of Pierre Gasly, Nico Hulkenberg, and Fernando Alonso, who managed a last-lap personal best but ended up in 14th place.

Further drama unfolded in Q1, as Alonso's spin at Turn 3 led to yellow flags being waved, preventing Esteban Ocon, Kevin Magnussen, Lance Stroll, and Lando Norris from setting faster lap times. Norris, after briefly attempting to set a time on medium tires, found himself in the drop zone and could not escape. Logan Sargeant briefly jumped ahead of Norris but ended up in 20th place due to a track limits infringement.

The session also saw peculiar incidents, including Tsunoda clipping a Williams jack while leaving the pits and several pitlane impeding incidents involving Verstappen, Russell, and Alonso.

As the dust settles, drivers involved in various incidents now await the outcome of post-session investigations. Verstappen, Russell, Norris, and Zhou are also under scrutiny for allegedly going too slowly on warm-up laps.

The stage is set for an exhilarating Mexican Grand Prix as Charles Leclerc and Ferrari appear to have found their stride, leaving Max Verstappen and Red Bull Racing with a challenge on their hands.

(Note: The information provided is based solely on the text provided by the user and may not reflect the actual events or outcomes of the F1 Mexican Grand Prix qualifying.)