The roars were back at the Riv on Thursday … and so was the rain.

After a four-birdie spree on the back nine at the Genesis Invitational, Englishman Aaron Rai vaulted into the lead at six under par through 16 holes before the horn sounded to suspend play at 5:41 p.m. He and 28 others will finish their first rounds when play resumes Friday morning at Riviera Country Club.

Unfazed by a nearly three-hour weather delay, Jacob Bridgeman fired a five-under 66 and shared the clubhouse lead with the No. 2-ranked player in the world, Rory McIlroy.

“Awesome course,” Bridgeman said as he left the press tent. “Played it yesterday for the first time and I love it!”

Making his tournament debut, Bridgeman carded four birdies on the back nine, the last at No. 17, to pull even with McIlroy at five under and parred the 18th. Bridgeman is ranked 52nd — the highest the 26-year-old South Carolinian has been since turning pro four years ago — but never has won on the PGA Tour.

“Today was about learning the course and finding the right spots,” added Bridgeman, who played at Clemson. “Florida is my comfort zone. I’ve never had any success on the West Coast, I never played out here in college, but I’m starting to figure out these Poa annua greens.”

While McIlroy is one of the most recognizable players on the planet, the casual golf fan might not have heard of Bridgeman before last week’s AT&T Pebble Beach Pro-Am, where he held the lead on the back nine and finished in a tie for eighth. He’ll become more well known — and $4 million richer — if he can keep his spot atop the leaderboard a few more days.

Tom Hoge carries an umbrella in the rain on the eighth hole during the first round of the Genesis Invitational.

Tom Hoge carries an umbrella in the rain on the eighth hole during the first round of the Genesis Invitational.

(Caroline Brehman / Associated Press)

Bridgeman never could have dreamed of a better “initiation” to Riviera than his 48-foot eagle putt on the par-five first hole.

“I got married Dec. 19 — maybe that’s my good luck charm,” he said.

McIlroy reached the green in two at No. 17 — the longest hole on the course at 590 yards — and two-putted to pull even. As the rain lessened, the wind increased, making holes 12 to 16 particularly challenging.

“I’ve gotten much more comfortable playing in conditions like this the last couple of years,” said McIlroy, who has 29 victories on the PGA Tour, most recently the Masters last April to complete a career Grand Slam. “I’m more prepared than I used to be. I have the skill set now to deal with it.”

In his pre-tournament news conference, the 36-year-old from Northern Ireland called the lengthening of the famed fourth hole by more than 40 yards — at 273 it is the longest par three on the PGA Tour — “a horrible change” but birdied it to get to three under.

After the Palisades fire forced the event to be relocated to Torrey Pines last February, it returned to its usual venue and, at least in round one, the iconic Riviera course held its own, as only 28 of the 72 players were in red numbers when play was suspended.

“Last year was just a horrific and terrible time for this entire community, people lost their lives, lost homes, lost valuables that they’ll never, ever be able to replace,” said tournament host and 15-time major champion Tiger Woods, who made his PGA Tour debut at Riviera as a 16-year-old amateur in 1992 but is not competing while recovering from lumbar disk replacement surgery in October. “For us to be able to come back here is great. Hopefully we can make a positive impact this week.”

The field features 41 of the top 50 players in the world rankings and 28 of the top 30 golfers from last year’s FedExCup standings. Viktor Hovland of Norway is tied for 12th at two under after back-to-back birdies to close out his round.

Rory McIlroy hits from a fairway rough on the eighth hole during the first round of the Genesis Invitational.

Rory McIlroy hits from a fairway rough on the eighth hole during the first round of the Genesis Invitational.

(Caroline Brehman / Associated Press)

“I liked my ball striking off the tee,” Hovland said. “Riviera really suits my game. Not the best putting, but I gave myself a lot of looks and my short game made up for some misses.”

Drawing the most attention in the morning was the threesome of McIlory, third-ranked Tommy Fleetwood and fifth-ranked La Cañada native Collin Morikawa, who was coming off Sunday’s one-shot win at Pebble Beach.

“I’m trying to keep the same mindset,” Morikawa said after six birdies, nine pars and three bogeys left him in a six-way tie for fifth at three under. “Back and forth, it was a long day. Rain, no rain, wind, no wind. For a stretch there it was hit and hope. It’s nice to be off to a good start and near the lead. We’ll see low scores over the next 54 holes.”

Fleetwood had two bogeys and a birdie on the front nine but settled down from there. He birdied the 11th and eagled the 17th to finish at two under.

A drizzle and chill could not discourage hundreds of fans with umbrellas from lining the fairways to cheer for their favorite players on the 100-year anniversary of the tournament originally called the Los Angeles Open. It debuted at Los Angeles Country Club in 1926 and this is the 61st time Riviera has hosted, including all but three since 1973.

The sun was shining and the clouds were gone by the time world No. 1 Scottie Scheffler, playing in the third-to-last group with Si Woo Kim and Xander Schauffele, teed off at 2:19. Scheffler struggled from the outset, carding three bogeys and a double bogey with no birdies and is tied for last with Keegan Bradley at five over through 10 holes.

“This is a golf course that’s stood the test of time,” Scheffler said after Wednesday’s pro-am. “Overall, if you execute out here, you’re going to get rewarded for it.”

Scheffler has won three majors, giving him four total, since he tied for 10th at Riviera two years ago. He won his season debut, the American Express, on Jan. 25 in La Quinta, and his nine consecutive top-four finishes are tied for the most on tour since 1983.

Rai, who turns 31 on March 3, has eight wins since turning pro in 2012, including the Wyndham Championship in 2024.