Nico Rosberg set the fastest time in Saturday’s final practice session at Mexico City’s Autodromo Hermanos Rodriguez, just ahead of Lewis Hamilton, but Kimi Raikkonen's morning ended early with an apparent engine failure.
Daniil Kvyat was fifth fastest for Red Bull, ahead of Force India's local hero Sergio Perez.
Story of the session
The running began in sunshine, with clouds staying in the distance and no threat of rain.
Perez briefly topped the times early on, despite an off-track adventure at Turn 7: "Very slippery out there; very difficult to find any grip," he reported.
Williams's Felipe Massa worked his way into the 1m23s bracket on a long run on the medium-compound tyre, topped by the second Force India of Nico Hulkenberg on 1m23.506s.
Kvyat lowered the top time to 1m23.029s, three tenths up on Rosberg, then dipped to 1m22.955s. Teammate Ricciardo just beat him on 1m22.090s, and then swapped the fastest time with Massa as the track evolved.
Hamilton appeared on his mediums after half an hour, immediately lapping within 0.002s of Ricciardo. "It's really hard to keep the tyres in the window," reported Hamilton on his long run.
The big news of the first half of the session was Kimi Raikkonen's Ferrari grinding to a halt with clouds of smoke from his engine bay.
"I have some issue with the engine, vibration at the end of the main straight and I have no power," said Raikkonen.
Crucial soft-tyre runs
This session was always going to be about the times on the softs. Vettel was the first to try them relatively early on, and duly took the top spot on 1m21.871s, half a second clear of FP1 pacesetter Verstappen.
Vettel's second flying lap was faster until he ran wide at Turn 12 and aborted the lap.
Impressively, Hamilton beat Vettel's soft-run time on medium tyres by 0.031s on 1m21.840s. Rosberg had set the second-fastest medium time on 1m22.329s, ahead of Ricciardo and Kvyat.
The soft-run flurry started in earnest with 12 minutes to go. Ricciardo went P3 on his first flying lap on 1m22.002s.
Rosberg set the new bar at 1m21.205s, with Kvyat second fastest on 1m21.530s, 0.325s slower than the Mercedes. Vettel reappeared in P2 on 1m21.294s on his second run on the softs, showing their durability.
Rosberg lowered his fastest time to 1m21.083s, as Hamilton complained that "Nico was backing me up" before Lewis ran off on to the grass at Turn 1 on his first attempt.
Ricciardo then set the second-fastest time of 1m21.201s after a handful of laps on his soft tyres, but that was eclipsed by Hamilton's 1m21.150s despite a lock-up at Turn 13.
Hamilton improved to a 1m21.097s late on, but couldn't topple his teammate.
Behind Ricciardo, Vettel, Kvyat and Perez, Williams's Valtteri Bottas was seventh, just ahead of Toro Rosso's Carlos Sainz. Massa was ninth, ahead of Hulkenberg and Verstappen.
The Lotus of Pastor Maldonado and Romain Grosjean were next up, from Sauber's Marcus Ericsson, Fernando Alonso's McLaren, and the second Sauber of Felipe Nasr.
Behind Raikkonen, Will Stevens regained the upper hand in the Manor battle over Alex Rossi.
In other incidents, Kvyat spun at Turn 8 at the end of a medium-tyre run, and Jenson Button lost most of the session with an ERS problem and was last.
Sainz mistakenly visited the Force India pits after he'd had an off-track excursion.
|3||Daniel Ricciardo||Red Bull Racing||1:21.201||+0.118||21|
|5||Daniil Kvyat||Red Bull Racing||1:21.530||+0.447||27|
|6||Sergio Perez||Force India||1:21.603||+0.520||27|
|8||Carlos Sainz Jr.||Toro Rosso||1:21.775||+0.692||28|
|10||Nico Hulkenberg||Force India||1:22.010||+0.927||25|
|11||Max Verstappen||Toro Rosso||1:22.039||+0.956||31|
|12||Pastor Maldonado||Team Lotus||1:22.042||+0.959||21|
|13||Romain Grosjean||Team Lotus||1:22.184||+1.101||24|