Seamus Power and Padraig Harrington also in action at Pebble Beach
Shane Lowry is making solid progress at the fog interrupted AT&T Pro-Am as his second round leaves him 5-under overall and five off the leading trio.
The Offaly man and fellow Irish golfer Seamus Power, who represented Ireland at the Olympics alongside Padraig Harrington, were both on 4-under, before a birdie for Lowry on the 16th pushed him ahead.
Harrington is further back on 3-over after carding a 1-over round with a birdie on the final hole pushing him slightly up the leaderboard.
There is a three way tie for the lead. Two time major winner Jordan Speith, World No 1 Jason Day and Derek Fathaeur share the lead on 10 under par.
That trio hold a strong four shot lead over their nearest challengers who are on 6-under. That latter group includes Brandt Snedeker and Patrick Reed.
Just one shot behind them on the leadeboard is Lowry who enjoyed a solid bogey free round where he picked up three shots for the day.
Power birdied the 2nd, 6th and 18th, with his only setback coming with a bogey on the 16th.
Pebble Beach views. 💯 pic.twitter.com/tYGO5rtUtM— PGA TOUR (@PGATOUR) February 11, 2017
It was a tale of two halves for Harrington as he carded bogeys on the 1st, 6th and 7th holes, having birdied the 13th and 16th either side of consecutive bogeys on the 14th and 15th.
But a birdie on the last saw him card a 72.