Simmons, who plays for Mumbai in the Indian Premier League, only arrived in the country on Tuesday as a replacement for injured all-rounder Andre Fletcher.
The same fans who cheer him in the domestic T20 tournament were reduced to stunned silence as Simmons bludgeoned 82 not out to lead West Indies to their target of 193 with two balls to spare.
Simmons was caught three times but made the most of his fortunate reprieves as West Indies clinched a final meeting with England on Sunday.
On 18 and 50 he escaped after the bowlers had overstepped for no-balls.
The 31-year-old also had luck on his side on 68 when Ravindra Jadeja snapped him up on the boundary but stepped on the rope as he lobbed the ball to Virat Kohli, turning a possible dismissal into a six.
“Today was my day…I had luck on my side and things went the way we wanted them to,” Simmons told reporters after his team’s seven-wicket win.
The first no-ball came from spinner Ravichandran Ashwin who had a tough time trying to grip the wet ball in the evening dew.
Paceman Hardik Pandya was the offender on the second occasion with Ashwin the fielder taking the catch. Simmons took full advantage of that no-ball by blasting the resulting free hit for six.
“The only thing I’m disappointed about are the two no-balls,” said India captain Mahendra Singh Dhoni.
“The points at which the no-balls were bowled were quite crucial. If we had got those wickets we would have got the opportunity to bowl one or two overs with the spinners and get away with them without giving away too many runs.”
(Editing by Tony Jimenez)