Dustin Johnson fired a seven-under 64 to climb into a share of the Pebble Beach Pro-Am lead after the second round.
The world number one made eight birdies on the Monterey Peninsula Country Club course to move into 12 under in Pebble Beach, California, on Friday.
A two-time winner of the PGA Tour event, Johnson started on the back nine and holed five birdies, before three in four helped him into the lead.
Johnson has made a fine start to this year, winning the Tournament of Champions before a top-10 finish at the Abu Dhabi HSBC Championship.
Joining him atop the leaderboard is fellow American Beau Hossler, who carded a five-under 67 on the Spyglass Hill Golf Course.
Hossler backed up his opening-round 65 with a bogey-free Friday.
Troy Merritt (67 on Spyglass Hill) and Julian Suri (67 on Monterey Peninsula) are two shots back in a tie for third.
A further shot adrift are the likes of four-time champion Phil Mickelson, Spaniard Jon Rahm and Australian Jason Day.
Rahm, the in-form world number two, carded a second straight 67 to be in the six-man group at nine under.
Day and Mickelson fired six-under 65s on Monterey Peninsula, with Aaron Wise, Kevin Streelman and Steve Stricker joining the group in a tie for fifth.
Defending champion Jordan Spieth managed to get going, shooting a five-under 66 on Monterey Peninsula to be tied for 23rd.
Making his first PGA Tour appearance of the season, Rory McIlroy struggled on the same course.
The Northern Irish four-time major champion carded a 74 to slip back to one under as he endured a forgettable few moments on the par-four fifth hole.
McIlroy had an eagle putt at the hole, but left with a double bogey after an implosion, before two more bogeys followed to finish his round.
19 de agosto 2018
|MLS Review: Royer leaves it late for Red Bulls, Dallas bounce back|
|Crotty concussed, Folau injured|
|DFB president Grindel sorry Ozil felt ´deserted´|
|Busch picks up first win of season in Night Race|
|NASCAR results at Bristol: Kurt Busch picks up first win of season in Night Race|
|Woakes welcomes back ´big-game player´ Stokes|
|´Genius´ Messi still amazes Valverde|
|All Blacks, Springboks await Namibia at Rugby World Cup|
|Federer to face Djokovic after Goffin withdraws|
|Rain halts plays at Wyndham Championship|
|De Gea will extend contract soon, says Mourinho|
|Halep to meet Bertens in Cincinnati final|
|Frampton set for Warrington fight after dominant Windsor Park win|
|Messi makes LaLiga history with Barcelona´s 6000th goal|
|MC Alger defeat throws quarter-final chase wide open|
|Barcelona 3 Deportivo Alaves 0: Messi´s milestone goal sets up victory|
18 de agosto 2018
|Djokovic on course for Masters 1000 history after Cilic victory|
|It´s on! - Wilder fight confirmed after Fury defeats Pianeta|
|Like Cruyff before him, Guardiola favouring Foden´s style over substance|
|Ronaldo tweets debut delight after Juve win|
|Chelsea are not title contenders yet, claims Sarri|
|Bayern Munich boss Kovac planning for Boateng stay|
|Championship Review: West Brom crush QPR as Leeds stay perfect|
|Allegri pleased with Ronaldo despite goalless Juventus debut|
|Chelsea can produce magic with Sarri in charge - Hazard|
|Emery ´happy without the result´ as Arsenal comeback falls short|
|Gordon confirms Cleveland Browns return|
|Eight shots and only 30 passes - Ronaldo´s Juventus debut in Opta numbers|
|Cristiano Ronaldo´s debuts: Best impressed, scoring a penalty & a blank for Juventus|
|Old boy Escare haunts Catalans in big Wigan win|
|Preston North End 2 Stoke City 2: Super sub Crouch salvages a point|
|Pochettino vows not to discuss Alderweireld future before five-minute answer|
|Waring, Aiken lead the way as Olesen stays in the hunt|
|Linking play, forcing saves and clashing with goalkeeper - Cristiano Ronaldo´s Juventus debut|
|Chelsea 3 Arsenal 2: Alonso snatches win after Gunners comeback|
|West Ham still haunted by last season - Pellegrini|
|Puel defends Vardy after Wolves red card|
|Chievo 2 Juventus 3: Ronaldo´s debut ends in dramatic win|
|Mbappe: Neymar is Paris Saint-Germain´s superstar|
|Pickford should have seen red - Hughes fumes over challenge on Ings|
|Kohli and Rahane star as India edge day one|
|AC Milan´s Strinic sidelined by heart problem|
|Kane happy to banish August goal hoodoo|
|Guingamp 1 Paris Saint-Germain 3: Mbappe returns to inspire comeback|
|Springboks´ second-half revival punishes Pumas|
|Finally! Kane scores a Premier League goal in August|
|Warnock enjoyed ´poetic justice´ of Kenedy´s penalty woe|
|Holders Eintracht Frankfurt stunned by Ulm in DFB-Pokal|
|West Ham 1 Bournemouth 2: Wilson, Cook condemn Hammers to successive losses|
|Tottenham 3 Fulham 1: Trippier and Kane help Spurs avoid Wembley wobble|
|Leicester City 2 Wolves 0: Lucky Foxes win despite Vardy red card|
|Everton 2 Southampton 1: Richarlison continues fine start|
|Drochtersen/Assel 0 Bayern Munich 1: Lewandowski spares Bayern´s blushes|
|Violent hack, no passes, missed penalty - Kenedy´s Cardiff nightmare|
|Ronaldo handed Juventus debut against Chievo|
|Cheika and Hooper frustrated by second-half slump|
|Hansen issues warning after All Blacks win Wallabies ´prizefight´|
|Stuttgart stay good for Pavard, says Reschke|
|You can´t buy class - United boss Mourinho blasts City documentary|
|Cardiff City 0 Newcastle United 0: Penalty miss rounds off abject day for Kenedy|
|Lopetegui open to rotating Real Madrid goalkeepers|
|´World´s best´ Alisson will be difficult to replace, says Roma boss Di Francesco|
|Dragons and Sharks pounce on Panthers after four get sin-binned|
|AC Milan situation has proved FFP works - UEFA president Ceferin|
|Marseille´s Garcia uninterested in striker despite Balotelli link|
|Goodhue sparkles on debut as All Blacks thump Wallabies|
|I feel like chicken tonight - Saunders game for a laugh after Wilder fowl play|
|Aubameyang-Lacazette partnership possible for Arsenal|
|Pant handed debut as India ring changes at Trent Bridge|
|Pochettino pledges to protect Kane|