He had guided her as a young girl on the driving ranges of South Korea; he had stood beside her as she won the US Women's Amateur Championship in 2011.
The 24-year-old was a simple two-foot putt away from her first ever senior victory, but the anguish of losing him to cancer in 2013 came flooding back.
"When I was playing in the US Women's Amateur, my dad was right next to me," said Kang. "I had that utter confidence that no one could get in my way, and all week I felt like that.
Kang is the first to admit she has endured a "really difficult road" in the ensuing years but as the crowd fell silent at Illinois' Olympia Fields Country Club and time slowed, she made no mistake, clinching the birdie to record her first win on the LPGA in 144 starts.
Ranked 43rd in the world coming into the tournament, Kang's previous best finish at a major was a tie for 14th at the US Open five years ago.
On Sunday, she walked away $525,000 richer, winner of the LPGA Championship.
'My week, my day'
Kang and South Korea's Chella Choi had started the final round tied for the lead at 10-under, but the greatest threat came in the group ahead, with 19-year-old Canadian Brooke Henderson maintaining the form that saw her win June's Meijer LPGA Classic.
Henderson, the defending champion, pushed Kang every step of the way, coming just a ball's roll away from an eagle on 18 that could have changed everything.
Unaccustomed to the lead, Kang admitted "every single shot was stressful."
Not that it showed.
A missed four-foot par putt as she started the back nine could have sent her stumbling, but instead it galvanized her.
"The three-putt on No. 10 was the turning point for me," she told reporters. "I just told myself that it was my week and it was my day."
Kang was determined she was going to learn from her error, and did so in spectacular fashion.
Making four consecutive birdies, Kang sunk putts of nine, 20, 30 and eight feet to establish a three-shot lead that would be reduced but not relinquished.
She closed with a round of 68 to finish 13-under-par, one shot clear of Henderson and the first player to win the LPGA Championship with a birdie on the final hole since Meg Mallon in 1991.
"Danielle played great" said Henderson, admitting there was "a little bit more pressure" coming into the tournament as defending champion and the woman to beat.
"I would have liked to have made one or two more putts on the back nine, but it was a great week for me."
The rest of the top seven was dominated by players from South Korea -- continuing a growing trend
-- with Chella Choi taking third (-10) followed by Mi Hyang Lee (-9), Amy Yang (-9), Sei Young Kim (-9) and Inbee Park (-7) who tied with America's Lexi Thompson.
But the day belonged to Kang, whose long wait for a first title came to an end on one of the biggest stages of all.
Her infectious smile had lit up the greens all week, but the tears of joy were welling up before the ball dropped into the cup.
Kang beckoned her mother onto the green before they embraced.
Her right hand displays a one-word tattoo: "Dad" in Korean and two weeks ago
, to celebrate Father's Day, Kang posted a photo of him on Instagram with the message: "I know you're with me every step of the way."
If there was one man missing from Sunday's celebrations, Kang had certainly done him proud.