Richie Porte (Trek-Segafredo) suffered mechanical problems on stage 18 of the Tour de France that nearly ended his hopes of a top-five finish, but after a frantic chase, he held on to fourth place overall with three days remaining.

Porte survived the final mountain stage of this year's Tour, as well as the final stage with its many climbs in the Alps, only to suffer a front wheel puncture on a treacherous gravel section on the final climb of the Glières plateau with 30km to go. Porte had to ride unassisted for a while, but eventually a team car arrived and provided him with a new bike.

To make matters worse, Mikel Landa and Enric Mas, the main rivals for the top five, kept pushing at the front of the race, trying to pull away from Porte and several other riders.

"It was a good push. I didn't know if I could go, but I guess I had to fight. The team supported me the whole way. I'm happy to win," Porte said with relief.

Porte, 35, came in contact on the last unclassified climb before the finish in La Roche-sur-Follon, thanks to assists from Wout Van Aert and Tom Dumoulin.

"At the end of the day, Roglic was also with Cous, a bit isolated. That helped me a little bit and they [Van Aert and Dumoulin] also helped me. It's good to have friends in the group and I would do the same for them if I could. I think the time trial is over now. It was hard to come back."

Porte admitted that even without the puncture and the long chase, he would not have attacked in the finale, but he heads into the mountain time trial with the possibility of moving up to third overall in Paris. Trek-Segafredo is currently in fourth place overall, 1:39 behind Astana's Miguel Angel Lopez.

"I've had another day down, but I want to get through tomorrow and have a good time trial."

Even if Porte does not improve his overall ranking, his fourth place in Paris is his best ever Grand Tour result, surpassing his fifth place in the 2016 Tour de France. It would also be a fitting finish to his career as a Grand Tour leader, given his move to Ineos Grenadiers, which will be announced after this race. Porte has said that he will spend the next two years riding for others as a superdomestique.