The 20-year-old fired a closing round of two under 70 for a tournament total of two over on the notoriously difficult Valderrama layout and walked away with a cheque for (equivalent) AUD$52,000.
Playing on invitation in European Tour events in 2019, Lee has impressed with two top tens already and he now appears assured on securing his full playing rights for Europe in 2020.
It was a roller-coaster week for Lee who opened with a round of 75, followed by a round of 67 on Friday, a 74 on Saturday.
Lee recorded a total of 19 birdies during the 72 holes but three double bogeys on Saturday proved very costly in his push for a top ten.
Jason Scrivener finished 26th, a shot behind Lee, while Wade Ormsby was the only other Australian to make it to the weekend and finished 56th.
The tournament was won by South African Christiaan Bezuidenhout who ensured his first European Tour title was a memorable one with a six-shot victory over a group of five players including pre-tournament favourite Jon Rahm.
Bezuidenhout is in his second season on the European Tour and last week finished 3rd at the BMW International.
The Sunshine Tour’s Rookie of the Year in 2017, Bezuidenhout endured a controversial amateur career in which he was suspended for administering Beta Blockers as a means of overcoming a speech impediment.
When tested during the British Amateur Championship in 2014, the drugs were detected and led to a two-year ban reduced to seven months.
“I was relieved, it was a long day, said the winner. “I went through a struggle in the middle of the round, three bogies in a row. I thought, I can’t let it slip.
“My caddie kept me in the moment nicely and the par save on the eighth hole was crucial. It just got the momentum going that I had lost a bit.
“To bounce back with three birdies in a row after that was nice and it settled the nerves a bit. To come out with a win today is special.
“My family have kept me humble throughout my career, they’ve supported me and thanks to them. I’m here because of them, it’s so special."
Bezuidenhout was also the recipient of a start at the Open Championship, the leading three players inside the top ten this week and not already exempt into the Open Championship earning the right to play at Royal Portrush.
“It’s been a dream since I started playing golf to play in a major championship, and to play The Open, which is my favourite major, just makes it even more special.”
The two other places went to Adri Arnaus and Mike Lorenzo-Vera.
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