Jon Rahm has shown a remarkable tendency to achieve great feats quickly. Last year he secured his US PGA Tour card in only four starts, in January he won his first Tour title in just his 12th start as a pro and now, as the European Tour’s newest member, he is leading the first World Golf Championship of the year, in Mexico.

Well, co-leading as he is level after the first round on four-under 67 with Phil Mickelson, Lee Westwood, Ross Fisher, Jimmy Walker and Ryan Moore. Another stroke back joint seventh are Sergio García, Rory McIlroy, Thomas Pieters, Fabrizio Zanotti, Chris Wood, Matt Kuchar and Pat Perez.

The last time six players were tied for the lead after the first round on the PGA Tour was the 2015 Genesis Open, with the same situation occurring three months earlier at the 2014 OHL Classic at Mayakoba. The most ever tied for the lead through 18 holes on the Tour was nine at the 2011 Genesis Open.

Interestingly, four players in the field this week also teed up in the WGC American Express Championship at Valderrama in 1999 (famously won by Tiger Woods on the first hole of sudden-death against Miguel Ángel Jiménez): Westwood, Mickelson, Garcia and Jim Furyk (77). It was the only WGC originally designed to travel around the world. When the PGA Tour couldn't secure a sponsor for the scheduled 2017 WGC event at Trump Doral outside Miami, it was moved to Mexico City.

Earlier in the week, the European Tour announced that Rahm (and American Kevin Na) had officially become members.

Said Rahm of his new membership, “I have always wanted to play the Ryder Cup and I have always wanted to be a member of the European Tour. I have obviously taken a different approach to tour life than a lot of other Europeans who went to college in the States, but I thought this was my best shot. I’m surprised I have been able to take this opportunity so early but it’s great to be able to join.

“I have so many memories of the European Tour – one that stands out was watching Justin Rose’s hole-in-one on the third hole at the Volvo Masters the year he won the order of merit at Valderrama. I remember Miguel winning the French Open; Pablo winning the French Open and then Pablo and Sergio’s play-off at the BMW International too. I’m really looking forward to playing some tournaments on the European Tour.”

If they stay inside the world’s top 50, Rahm and Na would be eligible to play in any of the first five tournaments in the European Tour’s new Rolex Series – an alliance of eight events each with a minimum prize fund of US$7million.

Rahm has already represented Spain in the ISPS Handa World Cup of Golf, finishing eighth alongside Rafa Cabrera-Bello in Australia last November.