Force India deputy boss Bob Fernley hailed the team's relentless progress after they secured fourth place in the constructors' standings in Mexico.

Esteban Ocon and Sergio Perez battled to fifth and seventh at the Autodromo Hermanos Rodriguez, opening up an unassailable 99-point lead over nearest rivals Williams.

The team have emerged supreme in an intense midfield scrap, finishing a lucrative fourth for the second year in succession with a record points tally.

"It's fantastic to confirm fourth place in the championship with a competitive race in front of so much support from the Mexican fans," Fernley enthused.

"For a while the podium looked to be within reach for Esteban until the Virtual Safety Car handed the advantage to [Kimi] Raikkonen and also brought [Lance] Stroll into play.

"Esteban had to work hard for the final 20 laps fending off the Williams and did a fantastic job despite being on older tyres.

"Sergio made a late pit stop for some new ultrasoft tyres and was catching Stroll quickly, but we just ran out of laps.

"This result is another demonstration of the progress we have made this season and fourth place in the championship for the second year in a row is a wonderful reward for the entire team."

Ocon climbed to third at the start, capitalising on the turn three incident between Lewis Hamilton and Sebastian Vettel, but would be denied a maiden podium by Ferrari's fightback.

"For a while I believed the podium was possible because I was sitting in third place for so long," the Frenchman said.

"I made a great start and then I pushed as hard as I could in the free air. Sadly the Virtual Safety Car gave Kimi an advantage during the pit stops and he was able to overtake us.

"The final few laps of the race with Stroll behind me were not easy. He had fresher tyres and managed to catch me, so I had to give it everything to stay ahead.

"When you work so hard for a result it feels very satisfying."