Porsche was never threatened by rival Toyota over the course of the six-hour race, the two 919 Hybrids finishing a lap clear of the Japanese cars. 

The margin in favour of the championship leaders over teammates Nick Tandy, Andre Lotterer and Neel Jani was just seven seconds at the chequered flag.  

The lead for the Hartley car had been as much as nearly half a minute after Lotterer had to take drive-through after a problem with the pitlane limiter led to a speeding offence, but Jani cut a 20s deficit to Bernhard in half over the course of the final stint as the German driver backed off. 

The drive-through and a change of fuel flow meter for the winning cars were the only hiccups encountered by Porsche on the way to a third consecutive victory.

Hartley said: "It was an awesome race by the Porsche team. I said after qualifying that we had a great car from the first laps and only needed to make small tweaks. 

"The team made the lives of us drivers easy and we had a fairly smooth race."

Toyota finished a lapped third and fourth as its TS050 Hybrid was not a competitive proposition in Mexico City, the car lacking downforce at the high-altitude track. 

The #8 entry that finished third in the hands of Sebastien Buemi, Kamui Kobayashi went a lap down just three hours and 20 minutes into the race. 

Rebellion on top in LMP2

The Anglo-Swiss Rebellion Racing squad took its first LMP2 victory with the best of its pair of Oreca 07s driven by Bruno Senna, Nicolas Prost and Julien Canal. 

Senna came through from third on the grid to build up a 30-second lead in the early stages and Prost and then Canal maintained first position apart from a brief period in the penultimate hour. 

Ben Hanley moved into the lead in the best of the Manor Orecas and Senna had a quick spin as he strived to catch the Briton. 

But Senna moved back into the lead when Hanley had to take tyres at the Manor car's final pitstop.

Hanley, who shared with Matt Rao and Jean-Eric Vergne, looked destined to take second after passing Nicolas Lapierre in the Signatech Alpine, only to spin in the closing stages. 

That allowed the Signatech car, co-driven by Gustavo Menezes and Andre Negrao, to take second place, 25s seconds behind Senna. 

The points-leading Jackie Chan DC Racing trio, Oliver Jarvis, Ho-Pin Tung and Thomas Laurent, were classified last in class and eight laps down due to a clutch issue.

Aston wins GTE Pro

Aston Martin claimed GTE Pro honours with Marco Sorensen and Nicki Thiim. 

Their Vantage GTE battled with the Ferrari 488 GTE shared by Sam Bird and Davide Rigon for much of the race and was in the lead when it stopped under a full-course yellow virtual safety car with just over an hour to go. 

Thiim trailed the Ferrari, which ended up making one pitstop fewer, to the flag by just eight tenths of a second, but the Italian car had already been awarded a 10s time penalty for speeding during the full course yellow. 

That gave Sorensen and Thiim the victory by just over 9s when the results were adjusted. 

No one else was in contention in GTE Pro, Frederic Makowiecki and Richard Lietz ending up a lap down in third in the best of the factory Porsche 911 RSRs, while the top Ford of Andy Priaulx and Harry Tincknell was a further lap back in fourth.

The second Aston Martin of Darren Turner, Jonathan Adam and Daniel Serra had to retire due to brake issues.

The GTE Am class was won by the Dempsey-Proton Porsche 911 RSR shared by Christian Ried, Marvin Dienst and Matteo Cairoli, who finished a lap ahead of the Aston Martin Vantage GTE shared by Pedro Lamy, Mathias Lauda and Paul Dalla Lana.

Pos.	#	Drivers	Car	Class	Gap
1	2	Timo Bernhard   Brendon Hartley   Earl Bamber	Porsche 919 Hybrid	LMP1	240 Laps
2	1	Andre Lotterer   Neel Jani   Nick Tandy	Porsche 919 Hybrid	LMP1	7.141
3	8	Anthony Davidson   Kazuki Nakajima   Sébastien Buemi	Toyota TS050 Hybrid	LMP1	1 lap
4	7	Kamui Kobayashi   Mike Conway   Jose Maria Lopez	Toyota TS050 Hybrid	LMP1	1 lap
5	31	Bruno Senna   Julien Canal   Nicolas Prost	Oreca 07	LMP2	21 laps
6	36	Nicolas Lapierre   Andre Negrao   Gustavo Menezes	Alpine A470	LMP2	21 laps
7	24	Jean-Eric Vergne   Ben Hanley   Matt Rao	Oreca 07	LMP2	21 laps
8	26	Roman Rusinov   Pierre Thiriet   Alex Lynn	Oreca 07	LMP2	21 laps
9	13	Nelson Piquet Jr.   David Heinemeier Hansson  Mathias Beche	Oreca 07	LMP2	22 laps
10	37	David Cheng   Tristan Gommendy   Alex Brundle	Oreca 07	LMP2	22 laps
11	28	François Perrodo   Emmanuel Collard   Matthieu Vaxiviere	Oreca 07	LMP2	22 laps
12	25	Vitaly Petrov   Simon Trummer   Roberto Gonzalez	Oreca 07	LMP2	23 laps
13	38	Oliver Jarvis   Ho-Pin Tung   Thomas Laurent	Oreca 07	LMP2	29 laps
14	95	Marco Sorensen   Nicki Thiim	Aston Martin Vantage	LMGTE PRO	31 laps
15	71	Sam Bird   Davide Rigon	Ferrari 488 GTE	LMGTE PRO	31 laps
16	91	Richard Lietz   Frédéric Makowiecki	Porsche 911 RSR	LMGTE PRO	32 laps
17	67	Harry Tincknell   Andy Priaulx	Ford GT	LMGTE PRO	33 laps
18	92	Michael Christensen   Kevin Estre	Porsche 911 RSR	LMGTE PRO	33 laps
19	51	James Calado   Alessandro Pier Guidi	Ferrari 488 GTE	LMGTE PRO	34 laps
20	66	Stefan Mücke   Olivier Pla	Ford GT	LMGTE PRO	35 laps
21	77	Christian Ried   Matteo Cairoli   Marvin Dienst	Porsche 911 RSR (991)	LMGTE AM	36 laps
22	98	Pedro Lamy   Paul Dalla Lana   Mathias Lauda	Aston Martin Vantage	LMGTE PRO	37 laps
23	86	Michael Wainwright   Ben Barker   Nick Foster Jr.	Porsche 911 RSR (991)	LMGTE AM	37 laps
24	54	Francesco Castellacci   Miguel Molina   Thomas Flohr	Ferrari 488 GTE	LMGTE AM	39 laps
25	61	Matt Griffin   Mok Weng Sun   Keita Sawa	Ferrari 488 GTE	LMGTE AM	41 laps
26	97	Darren Turner   Jonathan Adam   Daniel Serra	Aston Martin Vantage	LMGTE PRO	157 laps