World number two Jon Rahm showed his class at the Mexico Open on Friday, claiming the outright lead after round two at 12 under.

Rahm was the joint-leader after a bogey-free first round, and kept that momentum going with another eight birdies the second time around, although they did come with three bogeys.

Two shots back at 10 under is Alex Smalley, who shot an incredible 30 on the front-nine thanks to birdies on two, six and seven, and an eagle on the par-four third hole. He finished with a second-round 66, one stroke off the round of the day.

A small group at nine under is in a tie for third, including Patrick Reed, Cameron Champ and Adam Long, who also all shot 66.

The next logjam at eight under includes Davis Riley, who was one of four players to shoot Friday's best score of 65 – along with Martin Trainer, Emiliano Grillo and Doug Ghim, with that trio all at five under after posting 72s in the opening round.

Also at eight under is Kurt Kitayama and Jonathan Byrd, who shared the first-round lead with Rahm, but could only manage 70s to now sit four strokes off the Spaniard.

A strong international contingent sits at six under in a tie for 18th, featuring England's Matt Wallace, India's Anirban Lahiri, Thailand's Kiradech Aphibarnrat and Japan's Satoshi Kodaira.

Kevin Na is one shot further back at five under, along with the leader of the Mexican contingent, Alvaro Ortiz, who birdied five of the first seven holes, but a double bogey on eight and two more bogeys on 10 and 13 wiped out a lot of his good work.

The higher-ranked players in the field, such as Cameron Tringale (four under), Tony Finau (three under) and Abraham Ancer (two under) will live to see the weekend as the cut-line landed on two under.

Camillo Villegas, Adam Schenk and Scott Gutschewski were disappointing, missing the cut after solid first rounds in the 60s, with all three of them posting second rounds of at least two over.