Former Liberty Professionals midfielder Latif Blessing was on target for Los Angeles FC in their 3-1 win over Mexican side Club America.
The win helped LAFC to progress to the 2020 Concacaf Champions League final.
With the MLS trailing one-nil at half time and a man down following the sending off of midfielder Eduard Atuesta, head coach Bradley brought in the Ghanaian winger.
Blessing replaced Danny Musovski.
He scored the assurance goal in the 95th minute when he knocked home a rebound after Rossi's breakaway attempt.
It was Club America who shot into the lead in the 11th minute when Sebastian Caceres flicked home a corner kick at the near post.
LAFC swiftly turned things around in the second half when Carlos Vela scored twice in a 72-second span.
His equalizer was in the 46th minute when capitalizing on a turnover from Caceres, scoring 13 seconds after play resumed.
Vela gave LAFC the lead in the 47th minute by latching onto a long ball.
Kwadwo Opoku, the other Ghanaian player on the roster of LAFC, was an unused substitute.
LAFC will face another Mexican side in the final on 22 December, 2020 against Tigres UANL.
— LAFC (@LAFC) December 20, 2020