Porsche has survived a pulsating 6 Hours of Mexico while Audi has let victory slip from its grasp in Round 5 of the World Endurance Championship.

Timo Bernhard held on to supply the #1 Porsche 919 Hybrid he shares with Mark Webber and Brendon Hartley with their second successive win.

As rain intervened yet again inside the final 15 minutes, the Porsche beat Andre Lotterer who shared the #7 Audi R18 e-tron quattro with Marcel Fassler.

Stephane Sarrazin claimed third in the Toyota TS050 he crewed alongside Mike Conway and Kamui Kobayashi.

The race was spiced with tense theatre which continued through to five minutes from the end when Bernhard speared off on a slippery kerb before recovering to score by just over a minute after 230 laps.

Audi, which had enjoyed a decided advantage over Porsche in the rain-affected race, played its last card with 13 minutes remaining when Lotterer pitted for intermediate tyres.

The #7 Audi earlier emerged as the great hope for Ingolstadt after its #8 machine looked a realistic winning contender before it was mired with issues.

The Championship leading Porsche of Marc Lieb, Romain Dumas and Neel Jani was fourth.

In a furious opening stanza to the race, Webber and Lucas di Grassi(#8 Audi)  were involved in a fierce battle.

By mid-race, spots of rain appeared before a full course yellow period was declared in order to clear debris from several points on the circuit.

It prompted a flurry of pit activity as Bernhard held the lead from Loic Duval in the #8 Audi.

While the caution conditions continued, Bernhard plunged down the pitlane entry but aborted at the last minute which later attracted a stop/go penalty.

The infraction saw the #1 Porsche drop from the lead to third with the #8 Audi regaining the lead from the #2 919 which was being handled by Marc Lieb.

As the storm clouds darkened, the race settled into a three-car race with less than five seconds covering Duval, Hartley and Lieb.

Duval then came under fire from the two Porsches as first Hartley swept to the lead and then Lieb blasted past into second.

With the rain increasing both Porsches pitted simultaneously which left Duval in the lead momentarily before he headed into the pits, handing over the controls to Jarvis as the team gambled with slick tyres.

But the move turned to disaster as Jarvis clobbered the wall before he managed to crawl back to the pits.

Jarvis said the pedal went to the floor as the team later discovered that there was a fault with the left front wheel bearing.

With just under two hours remaining, the #2 Porsche was forced into the pits to replace its damaged rear light assembly which dropped it to third place with the #7 Audi inheriting second.

The Audi rejoined sometime later but there were further problems with the brakes on the out lap for Jarvis as he was again forced to limp the R18 e-tron quattro to the pits.

The Audi was then beleaguered with hydraulic problems.

Andre Lotterer found himself in the lead in the #7 Audi after more pit stops for the Porsches before the #1 919 would retake the lead again.

With just over an hour remaining Lotterer was taking chunks out of the lead held by the #1 Porsche but he collected the wall, spearing into the run-off before he pitted for tyres.

The incident promoted Sarrazin into an unlikely second place for a period as the reigning world champion Porsche crew held sway at the front.

In LMP2 Rene Rast seemingly had the class win in his keeping before a front right brake failure with just over 30 minutes remaining cruelled his chances in the #26 G-Drive Oreca Nissan.

It left Fiipe Albuquerque, Bruno Senna and Ricardo Gonzalez to claim a slender win in the RGR Sport by Morland Nissan-powered Ligier.

In GTE Pro, Darren Turner claimed victory in the Aston Martin V8 Vantage alongside team-mate Richie Stanaway while GTE Am was taken out by Patrick Long in the Abu Dhabi Proton Porsche RSR he shared with Al Qubaisi Khaled and Heinemeier Hansson.

The WEC now moves to round 6 of 9 at the Circuit of the Americas in Texas in two weeks.

RESULT: Mexico 6 Hours

Points standings