Minjee Lee predicts her sibling rivalry will come to the fore when younger brother Min Woo chases major glory at this week's US PGA Championship in Oklahoma.
Min Woo will tee up at the PGA Championship for the first time on Friday buoyed by a record-setting Masters debut at Augusta National last month.
The 23-year-old briefly stormed into outright fourth on the leaderboard during the final round after equalling Augusta's lowest-ever front nine with a scintillating six-under-par 30 on championship Sunday.
He eventually finished tied for 14th behind champion and world No.1 Scottie Scheffler to showcase his major championship credentials.
Now Minjee says she wouldn't be surprised to see Min Woo contend in Tulsa, especially after her own LPGA Tour victory in New Jersey on Sunday.
Minjee broke through for her maiden major title at last year's Evian Championship in France straight after Min Woo won the Scottish Open in July.
And the rare brother-sister double may not have been a quirk of fate, with Minjee admitting she'd been spurred on by Min Woo's triumph.
Minjee has no doubts Min Woo is motivated to regain at least a semblance of family bragging rights this week at Southern Hills Country Club.
"He did write something on Instagram or somewhere that it will be a little motivation for him to win, or to play well," she said on Tuesday.
"We have a sort of silent rivalry. I obviously love seeing him do well and I'm going to support him either way.
"It's a little bit of fun for both of us. I'm two up on him at the moment so he better get a move on."
For the record, Minjee is technically nine up on Min Woo for professional tournament wins - and one up in the majors.
The 25-year-old is also 50 spots higher in the rankings after returning to world No.4 with her seventh LPGA Tour success.
She'd love to reach the summit for the first time but says continuing to perform well at the majors will take care of that.
The third women's major of the year is just around the corner, with the US Open being staged at Pines Needles Golf and Lodge in North Carolina from June 3-6.
"I still think I need to do quite a bit of work to get there (to No.1) but there's a couple of big events coming up and they're probably more of my focus," Minjee said.
"With three majors left this season, those will be my bigger focus."
Min Woo is among eight Australians in the PGA Championship field, headed by world No.4 Cameron Smith.
Adam Scott, Marc Leishman, former champion and runner-up Jason Day, Cam Davis, Matt Jones and Lucas Herbert bare also in the 156-man field.
