Rupganj however were restricted to 198-8 in 50 overs despite a 95-run knock from Asif Ahmed Ratul.
Pacer Mrittunjoy Chowdhury claimed 3-37 to wreak havoc on Rupganj batting line-up.
Rupganj were in sixth position so far with eight points from nine matches.
Meanwhile, Abahani Limited moved to the fourth position of the point table with 12 points from nine matches after a thrilling one-run victory over Gazi Group Cricketers at BKSP-3 ground on Monday.
Jaker Ali Anik struck a 103 ball-107 with 13 fours and two sixes as Abahani Limited posted 311-7. Afif Hossain hammered a brisk 32 ball-50 to complement Jaker.
Gazi Group battled hard but eventually were bowled out for 310 with Al Amin Junior making highest 92 and opener Mehedi Marud adding 82. Saifuddin of Abahani scalped 3 for 56.
In the day's other match, Mohammedan bounced back into the winning-way with a 5-run victory over City Club at BKSP-4 ground. But despite this victory their aspiration to move to the Super League remained in limbo.
Being sent to bat first, Mohammedan racked up 228-9, thanks to Abdul Majid's 64. Shuvagata Hom also played an crucial innings of 59 runs.
Pacer Hasan Mahmud then took 3-47 as City Club were wrapped up for 223 in 48.4 overs. Captain Jawad Royen top-scored with 69 runs.