The horn sounded to clear players and spectators from the course at 4:22 pm ET as winds picked up and lightning moved into the area. There was a brief weather-related suspension at 3:07 pm ET.
Koepka took advantage of ideal morning scoring conditions to put the LIV Golf flag a commanding four shots clear at the top of the Masters' early second-round leaderboard on Friday, as rain and thunderstorms took aim at Augusta National.
Koepka, who shared the overnight lead with Norway's Viktor Hovland (25) and Spain's Jon Rahm (28), returned a spotless five-under 67 to set a 12-under target for the afternoon wave that headed out under menacing skies.
Amateur Bennett continued to be the Augusta surprise package lurking four back with a round of 68, showing maturity that belied his status on the course
Resurgent Jason Day (35) had looked poised to challenge Koepka until he stumbled to a double-bogey, bogey, par, bogey finish for a disappointing 72 that put the Australian in the clubhouse seven behind.
Start times were pushed ahead by 30 minutes in an effort to get as much play in as possible before forecasted thunderstorms swept into Augusta.
Scoring is expected to get far more difficult on Friday, particularly for late starters like Rahm, who is in the second to last group out. It proved so, with the Spaniard battling to two-under after nine holes, a round he will have to finish in the morning at Augusta.
While Rahm, winner of three events already this season, was always expected to contend at the year's first major, Koepka was not.
But the four-time major winner, who is fit again after suffering a number of injury woes, has emerged as the leader of the LIV Golf contingent.
Koepka did all his damage on Augusta National's four par-five holes on Friday, recording three birdies and an eagle while taking a single bogey through two rounds.
"I just take it one shot at a time, one hole at a time, whatever I got in front of me," said Koepka. "I'm just interested in the shot I'm looking to hit at that current moment.
"It's just up to me whether I play good or not. Simple."
As Koepka was putting the finishing touches on his round, five-time Masters champion Tiger Woods (47) was teeing off.
Woods, who has never missed the Masters cut as a professional, will likely need to improve on his opening round 74 if he is to keep his streak alive. He was two-over through 11 holes when play was cut short.
Even in Thursday's superb conditions, Woods slumped to his worst opening round since 2005 and with the rain and cold sure to put his surgically repaired leg to an even bigger test, he will need to find some of the Augusta magic that earned him five Green Jackets.
Woods, who nearly lost his right leg in a 2021 car crash, was in the fourth last group with Hovland and Xander Schauffele (29).
Rory McIlroy (33) was unable to take advantage of an early start as his bid to complete the career Grand Slam slipped away again.
Making his ninth attempt to join the exclusive club the Northern Irishman finished five-over after the end of his second round and looks set to miss the projected cut of two-over.
