How Lewis Hamilton can seal world title No.4 in Mexico

Tech Corner: The challenges of Mexico (2:21)

Sam Collins joins Jennie Gow to explain why certain teams will be fearing the high altitude of the Mexican Grand Prix. (2:21)

MEXICO CITY -- Lewis Hamilton's victory in Austin inched him to the verge of this year's championship crown. The Mercedes driver holds a 66-point lead over Ferrari's Sebastian Vettel with three races, and 75 points, left to play for.

The permutations for this weekend are simple -- much like he had to do for his first championship at the 2008 Brazilian Grand Prix, he must finish fifth or better. Unlike that dramatic Sao Paulo climax, where he passed Timo Glock for fifth at the penultimate corner, he has two more races to secure the handful of points he needs this season.

By finishing fifth or higher, Hamilton will ensure he is at least 50 points ahead of Vettel with the final two races to space. Given Hamilton's recent form, it seems unlikely the championship will continue into Brazil without car failure or driver error.

The close fight in Austin should have served as a reminder of how close this championship could have been. It's also likely Ferrari will be left wondering what might have been in Mexico City, where Mercedes is braced for a difficult weekend at the high-altitude circuit.

With a resurgent Red Bull impressing every weekend, fifth position might well be a fair target for Hamilton and Mercedes this weekend. Though it features a long start-finish straight -- where Valtteri Bottas' Williams topped out at 372.54 km/h last year -- it also has two twisty, technical parts of the circuit likely to favour Ferrari and Red Bull. With Hamilton proving in Austin he has no desire to win the championship by collecting the points he needs to, all the ingredients are still in place for a classic contest.