Scottie Scheffler opened up a massive gap at the top of the Tour Championship leaderboard on Thursday.

The top-ranked golfer in the FedEx Cup standings gained six strokes on the field thanks to a masterclass on the back nine at East Lake Golf Club.

Scheffler owns a seven-shot advantage on his closest competition going into Friday's second round.

He entered the tournament with a 10-under score thanks to the staggered stroke start at the event. He now owns a huge cushion with three rounds to go.

Low scoring was the theme of the day outside Atlanta, as six players produced rounds of five-under or better to kick off the PGA Tour's season finale.

Scottie Scheffler Pulls Away Behind Incredible Back Nine

Scheffler turned into a birdie-making machine on the back nine.

The FedEx Cup leader started his run of birdies on the 12th hole. That began a stretch of three consecutive birdies.

Scheffler then finished his round with birdies at the 17th and 18th holes to move up to 16-under for the tournament.

Scheffler began the event at 10-under due to the staggered scoring start determined by the FedEx Cup standings.

Xander Schauffele was Scheffler's closest competitor within two strokes at the start, but now he and Collin Morikawa are tied for second at nine-under.

The incredible start should allow Scheffler to cruise to the tournament and FedEx Cup victories as long as shoots under par for the next three days.

Low Scores All Around East Lake

A handful of golfers in the 30-man field took full advantage of the scoring conditions around East Lake on Thursday.

Morikawa vaulted into the tie for second with Schauffele thanks to a five-under 66 that was one shot off of Scheffler's best round of the day.

Adam Scott, Taylor Pendrith, Justin Thomas and Aaron Rai all shot five-under 66s along with Morikawa.

In total, 27 of the 30 golfers in the field recorded an under par round and only Billy Horschel had an over-par Thursday.

The low rounds could be a sign of things to come for the tournament at a course that was redone recently.

Plenty of golfers could finish well into the double digits under par and that would make for some compelling competition for the spots beneath Scheffler in the FedEx Cup standings.

Xander Schauffele Turns in Average Afternoon

Xander Schauffele had a disappointing afternoon by his normal standard at East Lake.

Schauffele has never shot a round worse than 70 at the Tour Championship and he entered Thursday with a single even-par scorecard in his last 16 rounds at the course.

That's why it was so surprising to see Schauffele card a one-under 69 on Thursday.

He typically shines at East Lake, but he was unable to rediscover the magic in the first round, and in turn, he lost significant ground to Scheffler.

Schauffele is now staring at a seven-shot deficit, which could potentially grow larger if Scheffler plays well again on Friday.

The FedEx Cup title is not completely out of his sights yet, but Schauffele needs lower scores to challenge for that position.