Sergio Perez says he was relieved to finish the Malaysian Grand Prix, a race he labelled as the hardest of his Formula One career, after battling a virus throughout the weekend.
The Force India driver was struck down with an illness ahead of the weekend, but was still able to make the final part of qualifying and finish the race in sixth place.
A physically demanding circuit, coupled with hot and humid weather conditions, makes Malaysia one of the toughest grands prix of the season. Perez admitted he felt so unwell at times he thought he may be forced to sit out the action in Sepang, but expressed his gratitude to the circuit's doctors for helping him out during the weekend.
"It was probably the hardest race of my career, on a weekend in which I feared I would need to give up," Perez explained. "It is an amazing result just to make it to the finish: I just kept going out of willingness to do it and I have to thank the doctors for helping me out."
Perez made a fast start to move from ninth to sixth, and ran as high as fifth place after overtaking McLaren's Stoffel Vandoorne in the early stages. The Mexican held the position until lap 20 when he was passed by the charging Sebastian Vettel, who recovered from the back of the grid to finish fourth.
"Having a good start was the key to my race and so was passing Vandoorne during the first few laps. After that, I was able to manage my race and it was all pretty uneventful. We were able to extend the first stint and manage our tyres well.
"I was only under pressure from Vettel, but that was not really my fight. We scored some more important points for the team and I am happy to come home with a good result after such a difficult weekend. I hope to be back to full fitness in Japan."
The result has strengthened Perez' position in seventh place in the drivers' standings, with a 19-point buffer separating him from Force India teammate Esteban Ocon.