PEBBLE BEACH: Russell Knox matched his career low on the PGA Tour on Thursday by firing a six-under par 64 to seize a share of the first-round lead at the Pebble Beach National Pro-Am.

Knox, who birdied four of his final eight holes on the Shore Course on Thursday, shares the lead at six-under with American Hunter Mahan, who played the Pebble Beach Golf Links course.

The 156-player field rotates between three courses in the first three rounds, comprising Spyglass Hill, Shore and Pebble Beach, while playing with amateurs. Pebble Beach will host the final round. The 27-year-old Scotsman Knox played the back nine first on Thursday, making birdie at 11 and 12.

After a bogey on No. 14, he rolled in another birdie on No. 15 and then made it two in a row as he also birdied the par-four No. 16.

Knox moved to five under by making birdie at the sixth, and his final birdie of the day came at the par-four eighth.

Five-time PGA Tour winner Mahan needed a two-put for birdie on the 18th to grab a share of the lead. South Korea’s Noh Seung-Yul bogeyed his final two holes for a five-under 67. He was joined at minus-five by England’s Greg Owen, Japan’s Ryuji Imada and three others. Lee Westwood and Brandt Snedeker, who has finished runner-up at the last two tour events, are among nine players that are two strokes off the lead at minus-six.

Defending champ Phil Mickelson is tied for 57th after shooting a pair of late bogeys en route to a one-under 69.

Two-way tie in S.Africa

South African Richard Sterne and German Maximilian Kieffer shared the lead on 63 after the first round of the Joburg Open at the Royal Johannesburg and Kensington Golf Club on Thursday.

The pair are two strokes ahead of South Africans MJ Daffue, Bryce Easton and Tyrone Mordt as well as Swede Joakim Lagergren and American Peter Uihlein in an event co-sanctioned by the European Tour and the local Sunshine Tour.

David Horsey of England, Frenchman Alexandre Kaleka, Espen Kofstad of Norway and Brazilian Adilson da Silva are among a dozen golfers a further shot back on 66.