But despite his blockbuster opener, the 26-year-old's NBA career could have easily fallen into the dirt.
The 198cm shooting guard considered throwing in the towel after being shunned by NBA scouts in his time with the Sugar Land Legends in the semi-pro American Basketball League where he scored a mammoth 36.5 points per game.
"I almost quit after that," Simmons told ESPN in February.
"Before the first season of D-League, I played in the ABL and was like, 'This can't be what basketball is about.' I really wasn't exposed to overseas (basketball), and I really only watched NBA. In my era, we never really had anybody come and explain anything to us. I never really met scouts. I just didn't know about any of this type of stuff. All I knew was either you're gonna go to school or just go to work. That's where I was."
TURNING $150 INTO MILLIONS
Simmons made one last dash at the big league in 2013, forking out $150 to register for an NBA development league tryout.
It's been a wise investment as the young gun propelled his way through the D-League to earn a spot on the San Antonio roster - and an annual salary which has climbed from $525,000 last season to $874,000 this season and will hit $1.3 million next season.
"(Basketball) takes different people different paths," Spurs general manager R.C. Buford said in regards to Simmons' rollercoaster ride. "Clearly, his wasn't linear."
"There's a lot of places along the way where a guy in Jonathon's shoes could have fallen off the path. But he believed in himself."
Simmons credits his stoic work ethic to his success, saying he used to stand still for an hour each day and take countless shots at the hoop with his coach Chip Engelland.
"I worked my ass off to improve," he said. "Shoot, every day I kind of think and just reflect back on all it took to get to this point. I'm just continuing to stay humble about it because I want to keep getting better."
Spurs coach Gregg Popovich has been full of praise for the rising star, comparing his energetic game to NBA veteran Manu Ginobili.
"He's pretty fearless. He just goes and plays, kind of like Manu," Popovich said.
"He just dives into the game, and he competes. He really has great athletic skills. He's learning the game, and he's a quick learner, good worker. So he's got a chance to be a long-time player in the league if he pays attention and sticks to it."
Simmons is just happy to soak up the moment. "Really, that's what it felt like: a daydream," he told ESPN in February after being swamped by fans for an autograph.
"To see almost 500 people just waiting on me, it was like, 'What?' It was crazy that people wanted to come out and see me; not because I'm a Spurs player, but actually because people like the way I play.
"Like, I'm really sitting here, and a whole line of people are here for me to just sign autographs. I never thought that day would come."
