Sam Burns hits 61 to take one-shot halfway lead

Amateur Nick Dunlap is two shots off the pace at The American Express tournament.

Sam Burns watches his shot from the 17th tee at the Nicklaus Tournament Course at PGA West during the second round of the American Express tournament (Ryan Sun/AP) (AP)

Sam Burns shot a second round 61 as he took a one-shot halfway lead at The American Express tournament in California.

Burns’ career-low round leaves him on 17 under par, one shot ahead of fellow American Michael Kim with South Korean’s KH Lee and American amateur Nick Dunlap a further shot back.

A pair of eagles and seven birdies had put Burns in with a chance of breaking 60, but he could only par the last two holes.

Dunlap, who plays at the University of Alabama, fired a 65 at the Stadium Course – one of three being used for the tournament – to follow his opening 64.

A group of six, including American Ryder Cup star Patrick Cantlay and joint overnight leader Alex Noren of Sweden, sit on 14 under par.

Ireland’s Shane Lowry shot a second round of 67 to lie seven shots off the lead.