Mexican GP: Mercedes in front as Bottas dominates FP1

Bottas clocked a 1m17.824s on the ultrasofts to finish 0.466s clear of Hamilton, with Red Bull's Max Verstappen a further tenth adrift in third.

Bottas set the early pace on the supersofts, clocking a 1m19.614s, only to be deposed by Verstappen on the softs by half a tenth.

Hamilton moved to the top of the timesheet briefly before Sebastian Vettel became the first driver to dip into the 1m18s with a 1m18.824s on the supersofts.

Mercedes then turned its attention to the ultrasofts, with Bottas going quickest with a 1m17.824s and following that up with a second lap just 0.012s slower.

His teammate Hamilton was 0.789s off on his first run on the ultra-softs, losing time in the final sector.

Next time around, the championship leader had a slow middle sector, but closed the gap to just under half a second.

Ferrari and Red Bull opted not to run the ultrasoft tyres, saving them for the second session, and instead did their running on either the supe-soft or soft.

Daniel Ricciardo was fourth quickest, 0.026s slower than Red Bull teammate Verstappen, with Vettel the leading Ferrari in fifth.

Kimi Raikkonen was sixth, four tenths slower than Vettel, with Sergio Perez using the ultrasofts to end the session seventh in front of his home crowd.

There was frustration for the other Force India when Alfonso Celis Jr crashed at the final corner to bring out the red flag.

Celis, who was borrowing Esteban Ocon's car for FP1, lost the rear on entry to the final corner and hit the wall on the outside with the left-rear, breaking the rear wing.

Fernando Alonso, who will take a 20-place grid penalty for Sunday's race after engine component changes, was eighth, with Felipe Massa and Nico Hulkenberg completing the top 10.

Kevin Magnussen spent most of the session in the garage after the team discovered a water leak but got out in the closing minutes to clock the 13th fastest time.

Pascal Wehrlein was an impressive 14th quickest, ahead of both Toro Rosso drivers and half a second ahead of teammate Charles Leclerc, who was stepping in for Marcus Ericsson.

Brendon Hartley stopped out on track reporting an engine problem and though he managed to get his Toro Rosso going again to return to the pits, he didn't complete any further running.

He was 18th fastest, a tenth adrift of Sean Gelael, who was standing in for Pierre Gasly for this session.

Stoffel Vandoorne failed to set a time after Honda detected a potential issue in his engine data.

It came after Honda completed a full engine change ahead of the session in a bid to have relatively fresh elements for the final two races of the season.

When Honda detected the problem during FP1, it decided to revert to an older specification from Vandoorne's pool, which means no further penalty, while it investigates the issue.

Cla	Driver	Chassis	Engine	Laps	Time	Gap
1	Valtteri Bottas	Mercedes	Mercedes	42	1'17.824
2	Lewis Hamilton	Mercedes	Mercedes	35	1'18.290	0.466
3	Max Verstappen	Red Bull	TAG	16	1'18.395	0.571
4	Daniel Ricciardo	Red Bull	TAG	28	1'18.421	0.597
5	Sebastian Vettel	Ferrari	Ferrari	28	1'18.586	0.762
6	Kimi Raikkonen	Ferrari	Ferrari	27	1'19.008	1.184
7	Sergio Perez	Force India	Mercedes	21	1'19.240	1.416
8	Fernando Alonso	McLaren	Honda	20	1'19.346	1.522
9	Felipe Massa	Williams	Mercedes	32	1'19.443	1.619
10	Nico Hulkenberg	Renault	Renault	19	1'19.552	1.728
11	Carlos Sainz Jr.	Renault	Renault	24	1'19.554	1.730
12	Lance Stroll	Williams	Mercedes	34	1'19.772	1.948
13	Kevin Magnussen	Haas	Ferrari	16	1'20.644	2.820
14	Pascal Wehrlein	Sauber	Ferrari	30	1'20.971	3.147
15	Antonio Giovinazzi	Haas	Ferrari	26	1'21.269	3.445
16	Charles Leclerc	Sauber	Ferrari	28	1'21.446	3.622
17	Sean Gelael	Toro Rosso	Renault	29	1'21.639	3.815
18	Brendon Hartley	Toro Rosso	Renault	10	1'21.747	3.923
19	Alfonso Celis Jr.	Force India	Mercedes	17	1'22.342	4.518
20	Stoffel Vandoorne	McLaren	Honda	3