|Mexican Grand Prix coverage details|
|Venue: Autodromo Hermanos Rodriguez Dates: 30 Oct - 1 Nov|
|Coverage: Live text and radio commentary of all three days, plus TV highlights of qualifying and the race. Full details here.|
Nico Rosberg narrowly edged out Lewis Hamilton in a closely matched final practice session at the Mexican GP.
The German was just 0.014 seconds quicker than Hamilton despite an error from the newly crowned 2015 champion.
There was a hint of the tension between the two when Hamilton complained Rosberg was "backing me up" as they prepared for their fastest runs.
And they do not appear to have their usual advantage over the rest of the field, with Red Bull and Ferrari close.
Red Bull's Daniel Ricciardo was 0.118secs off the pace, 0.093secs ahead of Ferrari's Sebastian Vettel.
The Mercedes drivers clearly had some more time in hand as both made small errors on their fastest laps, but the same could be said of many drivers on the low-grip surface of the remodelled Autodromo Hermanos Rodriguez.
The newly resurfaced tension between the two Mercedes drivers comes after Rosberg was angry at what he described as the "extremely aggressive" move with which Hamilton took the lead at the first corner at the title-deciding US Grand Prix a week ago.
There was also an incident in the pre-podium room, where Hamilton tossed the second place cap to Rosberg, who promptly threw it back at him.
Hamilton has made it clear that despite achieving his lifetime's ambition and clinching a third world title, his desire is unquenched and his immediate target is to win the remaining three races of the season.
Complaints about the slippery surface abounded after Friday practice, and the drivers were mollified not at all on Saturday.
The aerodynamic excellence of the Red Bulls was underlined in the thin air at 2,300m in Mexico City, with Daniil Kvyat in fifth place.
The car was making up in the corners what it was losing down the long main straight.
The altitude means that the cars have neither the grip nor cooling they do normally, and the engines are also under extra strain.
Local hero Sergio Perez, cheered on by thousands of boisterous fans in the final part of the lap, where the track loops through a baseball stadium, was sixth.
Williams's Valtteri Bottas was seventh fastest, ahead of Toro Rosso's Carlos Sainz, Williams's Felipe Massa and the second Force India of Nico Hulkenberg.
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