Travelers Championship leaderboard: Scores from R1 at TPC River Highlands as Scottie Scheffler hits the front

Runaway World No.1 Scottie Scheffler was back to his best as he tied the lead after 18 holes of the Travelers Championship. 

Scheffler, who finished in the top 10 at last week's US Open, went round TPC River Highlands in 8-under 62 on Thursday. 

He shares the lead with Austin Eckroat and is two clear of Rory McIlroy, Keegan Bradley and Wyndham Clark. 

The 28-year-old American raced out of the blocks with two birdies in a row and made three more before hitting the turn in 5-under. 

Scheffler's back nine also included two more birdies and an eagle. 

His only mistake arrived at the par-5 17th when he was punished for a poor tee shot. 

Scheffler said he still found the conditions difficult. 

"I did a lot of good stuff," he said. "I felt like the conditions were pretty challenging out there, especially late in the day. I was able to hole some nice putts, as well."

European duo Tommy Fleetwood and Vitkor Hovland are among eight players currently on 4-under. 

Jordan Spieth was forced to withdraw for the first time in 297 starts on the PGA Tour with a neck injury. 

Spieth had only played 13 holes when he was taken off the course in a golf cart.

The aforementioned Clark confirmed he did damage a locker room door at Oakmont after missing the cut and regrets his actions deeply. 

McIlroy just wants to see good golf

McIlroy told reporters earlier in the week that although he did not contend at Oakmont last week he believed he had found something with his driver. 

He led the field at Oakmont in strokes gained off the tee and was excited to compete this week. 

"This is a nice tonic compared to last week in terms of it's a slightly more benign golf course and the penalty for missing isn't quite as severe," McIlroy said. 

"You can give yourself plenty of chances for birdies, which Keegan and I did today."

McIlroy has admitted he has felt a touch flat on the golf course since climbing his own personal Everest in May at The Masters. 

He said he wasn't bothered about making the cut at the PGA Championship and expressed his desire for a quick final round at the US Open last week. 

Asked what his attitude is this week, McIlroy said: "I just want to see some good golf and see some better shots. 

"I think if you concentrate on that and you're concentrating on your quality of golf and concentrating on just trying to play to the best of your ability, the result will take care of itself.

"There's no point in thinking about the result right now. 

"I'm just trying to play as good as I can and make good swings, and if I do that enough, more than likely I'll find myself in a position to have a chance to win."

View the full leaderboard here.