Bath finished second in their three-team group after 19-19 and 12-12 draws against London Irish and Northampton Saints respectively.
Banahan opened his account with an excellent try against his former club London Irish before scoring a last-minute try against Northampton when they were trailing 12-5.
The ensuing conversion meant that Bath had reached the quarter-finals of the competition by finishing second in their group.
Then, in the quarter-finals, despite losing 42-17 to NEC Harlequins, Banahan scored all three of his new club’s tries in that defeat.
Not unnaturally Banahan’s performances earned the 19-year-old top-billing on the Bath RFU club official website.