SAN FRANCISCO (AFP) - Australia's top-ranked Jason Day fired back-to-back birdies on Saturday (Feb 11) in finishing an eight-under-par 64 second round to grab a share of the lead at the PGA Pebble Beach National Pro-Am.

Day matched Americans Jordan Spieth and Derek Fathauer on 10-under par after 36 holes in the event, which is contested over three courses - Pebble Beach, Spyglass Hill and Monterey Peninsula.

Fog halted the second round Friday evening with 121 players yet to finish. The third round began even as the final golfers were concluding the second in hopes of finishing the event by Sunday night.

Day fired seven birdies in 12 holes at Pebble Beach before being halted Friday, closing with a run of three in a row.

He took a bogey at 13 when he resumed but answered with birdies at the par-5 14th and par-3 15th then closed the round with three pars in a row.

Spieth, a former world number one now ranked sixth, completed his round Friday, firing eight birdies at Spyglass Hill in a 65 to grab the clubhouse edge.

Fathauer parred one last hole at Pebble Beach on Saturday morning to complete a round of 64 to stand on 134, 10-under like Spieth and Day.

From there it was a hefty four strokes back to a fourth-place US pack on six-under - Patrick Reed, Pat Perez, Rick Lamb and Brandt Snedeker.

The schedule was fouled from the start with heavy rain and high winds late Thursday leaving all courses unplayable with 81 players forced to finish the opening round on Friday morning.