After claiming victory at the Memorial Tournament two weeks ago, Jon Rahm became the No. 1 golfer in the world for the first time in his career. And heading into the WGC-FedEx St. Jude Invitational, his focus is now on staying there.

The Spaniard overtook Rory McIlroy for the top spot but knows remaining at the summit will be an even greater challenge.

"Getting here, it's great," Rahm said, according to Rex Hoggard of The Golf Channel. "I played great golf the last four years, but I can keep playing that good or better to hopefully stay here for a long time."

Entering Thursday's opening round at TPC Southwind in Memphis, Tennessee, the 25-year-old doesn't have much experience at the course. He played there for the first time in last year's event and had a strong showing, finishing seventh at 10 under par, which included a 62 in his opening round.

Rahm will be playing against a competitive field this week, as 11 of the top 12 golfers in the world will be in action.

Here's everything else you need to know heading into Thursday's opening round.

Round 1 Information

TV: Golf Channel, 2-7 p.m. ET

Live Stream: GolfChannel.com and featured groups of PGA Tour Live.

Tee Times: The full list of Thursday tee times can be found at PGATour.com.

Odds

Rory McIlroy +900 (bet $100 to earn $900)

Jon Rahm +1000

Justin Thomas +1100

Bryson DeChambeau +1400

Xander Schauffele +1700

Patrick Cantlay +2000

Webb Simpson +2000

Daniel Berger +2500

Dustin Johnson +2500

Brooks Koepka +2500

Collin Morikawa +2800

Tyrrell Hatton +2800

Viktor Hovland +3000

Matthew Fitzpatrick +3000

Patrick Reed +3000

Hideki Matsuyama +3000

Billy Horschel +4000

Complete list of odds available at Caesars Palace

TPC Southwind is a course that typically yields positive results for Brooks Koepka. Last year, he won the WGC-FedEx St. Jude Invitational by finishing 16 under par, and he also owns a second-place finish (2016) and a third-place finish (2015) at the venue.

However, the 30-year-old hasn't been playing well of late, missing the cut at two of his last three tournaments and finishing tied for 62nd at the Memorial. At last week's 3M Open, he shot a 70 and 71, missing the cut at one under par.

Koepka is also still dealing with pain in his left knee after partially tearing his patella tendon last year, and according to ESPN's Mark Schlabach, the American "won't decide whether to have surgery until after this season."

For now, though, the world No. 6 is just seeking better on-course results:

"It's definitely been frustrating. It will test you mentally, but at the same time, I'm looking at it as a challenge and something where I know ... it will turn around eventually. It's going to turn around. You don't work that hard for nothing. Starting to see signs of it. Now it's just about going and doing it. Whether it be this week, next week, a month from now, two months from now, whatever it's going to be, it will pay off."

Another golfer looking to overcome some recent struggles is No. 5-ranked Dustin Johnson.

The 36-year-old won the Travelers Championship in June, but he hasn't fared as well in July. He missed the cut at the Memorial Tournament, shooting an 80 in each of the first two rounds. At last week's 3M Open, he shot a 78 in the opening round and then withdrew with a back injury.

But like Koepka, Johnson has had past success at TPC Southwind. He owns two career wins in the FedEx St. Jude Classic (2018 and 2012) and placed 20th in last year's tournament. He's also shot a 69 or better in nine consecutive rounds at the course, dating back to 2016.

Both men could be poised for bounce-back showings this weekend, but there's a lot of strong competition in the field, and golfers such as Rahm and McIlroy will always be a threat.

It should be a fun weekend with so many top golfers in the field looking for a final tune-up before next week's PGA Championship, and it could be a tournament that comes down to the wire on Sunday because of it.