Jason Kokrak earned a record lead at the AT&T Byron Nelson as two-time major champion Jordan Spieth sensationally missed the cut.
Kokrak was the star performer on Friday after carding an almost flawless eight-under-par 62.
The American's performance saw him move five shots clear to 12 under atop the leaderboard – the greatest 36-hole lead at the PGA Tour tournament since David Love III's four-stroke advantage in 2000.
Billy Horschel (65) is second heading into the weekend, but world number one Dustin Johnson is lurking in Irving, Texas.
U.S. Open champion Johnson posted back-to-back 67s to be tied for third at six under following the second round.
Teeing off on the back nine, Johnson was flawless as he birdied the 18th before adding another three consecutive birdies from the fifth to the seventh at Four Seasons Resort and Club Dallas.
Johnson would have been five shots adrift had he not bogeyed his final hole.
An Byeong-hun (66), Cameron Tringale (68), Bud Cauley (67), overnight leader James Hahn (70) and Jhonattan Vegas (68) are also six under.
Former world number one Jason Day is nine shots behind Kokrak following his second-round 69.
Masters winner and defending champion Sergio Garcia posted a five-under-par 65 to be two under through 36.
However, it was a day to forget for Spieth after he farewelled the tournament.
Spieth fired a five-over 75 with a quadruple-bogey nine on the par-five 16th hole as he missed the cut for the third time in four starts.
Spieth was well inside the cut line before the implosion that forced him to re-tee twice.
|Mourinho hugs reporter for asking about McTominay instead of Pogba|
|Di Francesco slams Roma: I should have substituted half of them!|
|Curtains for Konta and Ostapenko in Dubai|
|De Gea happy with ´important´ wonder save|
|Woods eager to experience Masters ´rush´|
|Vazquez and Asensio important to Madrid, says Zidane|
|Shakhtar Donetsk 2 Roma 1: Fred stunner seals first-leg comeback|
|Sevilla 0 Manchester United 0: De Gea ensures Mourinho´s men stay level|
|Klaasen and Duminy half-centuries set up T20 decider|
|Herrera injury gives dropped Pogba chance for reprieve|
|Tindall urges England to ´hunt´ vulnerable Scotland|
|Firmino insists he did not abuse Holgate|
|Leganes 1 Real Madrid 3: Casemiro inspires comeback for Zidane´s men|
|Milan have everything to lose – Gattuso worried about complacency|
|United a big team in defeat - Mourinho aims dig at City|
|Firmino escapes punishment after Holgate allegation|
|Mourinho benches Pogba for Sevilla clash|
|Cavendish withdraws after Abu Dhabi crash|
|Rugby greats put on show in French Alps snow|
|Gremio refute claims of €40m Arthur agreement with Barcelona|
|Messi will sign another Barcelona contract, predicts Bartomeu|
|UEFA rejects PSG appeal over Rabiot´s Real Madrid booking|
|Hardaker sacked by Tigers after failed drugs test|
|James to miss ´a few days´ of Bayern training with calf injury|
|Bellew not feeling Haye love|
|Nantes not stopping Ranieri if Italy come calling|
|Milan owner Li slams ´fake news´ over financial woes|
|Italy make three changes for France encounter|
|Wenger still gunning for top four spot with Arsenal|
|AFC Champions League Review: Kanazaki braces inspires Kashima|
|Gloucester centre Scott to re-join Edinburgh|
|Ospina to get Wembley nod as Wenger waits on Ramsey|
|Pogba not struggling at United, claims Deschamps|
|No police action against Gloucester coach Ackermann or son after nightclub incident|
|Australia proved a point with tri-series dominance, says Warner|
|Escape Messi´s shadow? Change sport! - Henry´s advice to Neymar|
|Scotland unchanged for crucial Calcutta Cup clash|
|Horsing around: Muller takes tips from equine companion|
|Lynn set for further assessment on dislocated shoulder|
|Ronaldo jets off for a break as Madrid head to Leganes|
|Bastareaud back in one of five France changes|
|Mistake to let Kroos leave Bayern for Madrid - Sammer|
|Short´s fifty and Agar´s spin seal deserved Australian tri-series win|
|Spalletti tips Ancelotti for Italy job|
|I can´t wait for retirement - Federer|
|Mendy on course for World Cup, says Deschamps|
|Man Utd on dismal knockout run, Roma have Shakhtar curse - Champions League in Opta numbers|
|Azpilicueta hoping for greater fortune at Camp Nou|
|Out of nothing he can score goals – Heynckes hails Muller|
|CONCACAF Champions League Review: Giovinco inspires Toronto, Tigres held|
|Steelers LB Shazier says he´s ´best linebacker ever´|
|Ranieri: I´ll quit Nantes if offered Italy job|
|Thiem keeps title defence on track, Monfils saves match point in Rio|
|Barcelona are great even without Neymar – Willian|
|Del Potro, Raonic progress at Delray Beach|
|Dolphins place franchise tag on Landry|
|Colts QB Luck ´extremely optimistic´ about shoulder rehab|
|Conte wants to see out Chelsea contract but has bags packed|
|A´s respond to Gruden´s belittling of Oakland|
|Yankees acquire Drury in three-team deal with Diamondbacks, Rays|
|Messi goal will give Barcelona more space at Camp Nou – Suarez|
|Serena Williams: I almost died|
|Conte defends ´incredible´ Christensen after Barcelona error|
|Bayern taking nothing for granted after 5-0 demolition – Heynckes|
|Valverde: Barcelona away goal not definitive for progression|
|Muller & Robben bemoan poor first half despite Bayern rout|
|Ivashka sets up Wawrinka Marseille meeting|
|Chelsea close to a perfect game against Barcelona - Conte|
|Defending for 90 minutes at Barcelona a ´suicide mission´ - Fabregas|
|Championship Review: Villa miss chance to move into promotion places|