The 26-year-old Australian entered the final round three shots back of Steele and hung tough through difficult conditions in Honolulu. He was able to cut his deficit to two shots heading into the 17th.
"Just had to hang in there. No one was playing good golf today, it seemed like," Smith said, according to The Associated Press' Doug Ferguson. "Just hung in there, and what do you know?"
No. 17 is when Steele began to unravel. He bogeyed the par-3 hole and hit a horrendous approach shot into the par-5 18th but was still able to salvage par. Smith, on the other hand, got up-and-down for birdie from the greenside bunker on No. 18 to force a playoff.
"Everything that could go wrong went wrong today," Steele said after letting his fourth PGA Tour win slip away.
Smith only needed to par the first playoff hole to secure his first individual PGA Tour title. He previously won the Zurich Classic team event in 2017.
Additionally, Smith pledged to donate $500 for every birdie he made throughout the week to help fight the wildfires devastating his native Australia. He made a total of 21 en route to his victory.
Here's how the leaderboard finished at the Sony Open:
|Place||Player||To Par||R4 Score|