Scottie Scheffler is the World No.1 and the ultimate competitor, even when facing his good friends on the golf course in the heat of battle.
The American, who claimed his second Tour Championship and FedEx Cup title just a few weeks ago, is back on the course in Team USA colors for the Presidents Cup.
Scheffler leads a strong US team against Geoff Ogilvy's International squad who are chasing just a second victory in the matches - and a first on US soil.
It means that for a third instalment of the Presidents Cup he will come up against his good friend Tom Kim.
Both players have qualified for the last two matches, and in 2024 went head to head on the opening day of competition.
Scheffler and Kim forged a friendship in Dallas after the latter moved to the US when he gained his PGA Tour eligibility and the pair became neighbors and practice partners.
Despite that friendship, Scheffler was happy to put things on hold as the draw for Day 1 at Royal Montreal pitched the American and his partner Russell Henley against Kim and fellow Korean SungJae Im.
In the third of the opening day's five fourball matches, Scheffler and Henley ran out 3&2 winners, as the US record a 5-0 clean sweep for the first time since 2000.
Scheffler and Henley were never behind in their match, but Kim and Im battled throughout - and it was never more evident than on the seventh hole.
Kim and Scheffler had both given themselves a chance of birdie on the par three hole with Kim draining his from around 30 feet.
Hoping to ignite the International's challenge, he let rip with a huge 'Lets Go', pumped his fist, spun a 360 on the green and stormed toward the hole.
An ice cold Scheffler, who has regularly played Kim for money during their practise rounds, stepped up and facing a putt of similar distance, drained the birdie attempt of his own to halve the hole.
The American's celebration saw him set off in pursuit of Kim, pointing toward his good friend and screaming 'What was that?'
There were smiles afterward, but there was no let up on the next hole, as Kim celebrated another birdie putt, with some equally demonstrative celebrations.
This time there were no words for Scheffler, or no chance for a reaction from the four-time major champion as the USA could not match Kim's four and the International pair headed straight toward the ninth tee trailing by one hole.
The next five holes were halved before two more birdies from Henley, on 15 and 16 clinched the point and there was no animosity after as Scheffler admitted everyone - even good friends - are fair game on the course.
"It's the same thing I would have done at home if he had made a putt, and he celebrated like that," he said after the match.
"It's all in good fun. We enjoy competing against each other, that's what it's like out here.
"It's fun to compete and fun to represent our country, and at the end of the match you take your hat off and shake hands.
"We're friends after, we're not friends during, I guess."
Scheffler will be captained this week by Brandt Snedeker, as the US chase their 14th outright victory.
Scheffler has never failed to be on the winning team - a far different story from his Ryder Cup record where he has lost two of his three appearances.
Only twice since the inaugural Presidents Cup in 1994 have the USA not emerged as the winning team.
Peter Thomson's International team got the better of Jack Nicklaus and Team USA at Royal Melbourne in 1998 with a 20/5 - 11/5 win, while the only time the match was tied was in 2003.
Since then it's been 10 consecutive victories for the US squad who are strong favorites to come away with the win in Illinois.
And with Scheffler fired up to win for his country - and beat his good friends in the process - the smart money is another big win.