Bagan won 3-1 to record back-to-back wins in the ISL.
The Yellow Brigade swapped Sahal for the defender for a fee of Rs 90 lakh.
The Kerala Blasters star is widely tipped to play for Mohun Bagan Super Giant this season.
India defeated Mongolia 2-0 with Lallianzuala Chhangte also scoring.
The 2021-22 ISL season saw Sahal play a pivotal role as Blasters entered the final for the first time since 2016. In 21 matches, he scored as many as six goals and had one assist.
The six final contenders picked by a three-member expert panel are: Eldhose Paul (athletics), Treesa Jolly (badminton), Abdulla Aboobacker (athletics), Sanju Samson (cricket), Sahal Abdul Samad (football), and S L Narayanan (chess).
The substitute scored two goals in the last five minutes to help Kerala Blasters post a 3-0 win.
The Kerala attacker equalised in the 43rd minute after Singapore took the lead six minutes earlier.
'Found my forever and made it official,' tweeted Sahal.
Sunil Chhetri had opened the scored from a freekick in the 86th minute.