After a goalless first half, the hosts, deservedly, scored in the 48th minute.
A good ball to Brian Ochieng found the Thika-based side off guard. The midfielder cut the ball back for Reagan to score what turned out to be the winning goal.
It was the Banker s sixth win in as many matches, and they are now on 18 points while Bidco are ninth on the log with seven points after as many matches.
At Wundanyi Stadium, Mathare United started their league campaign with a 4-2 loss against Sofapaka.
It took Batoto ba Mungu 12 minutes to take the lead when former Gor Mahia midfielder Juma Lawrence beat Job Ochieng from close range.