The fourth win of the season for RCB meant they now finish at the third spot on the table behind Delhi Capitals and Mumbai.
Perry, who had gone wicketless so far in the tournament, had a night to remember as she registered the best-ever bowling figures in the history of Women’s Premier League as RCB dismissed MI for 113, their second lowest score in WPL, after opting to bowl first.
Chasing 114 to win, RCB were 39 for 3 in the seventh over. It could have been worse had Nat Sciver-Brunt held on to two catches off Shabnim Ismail.
However, the 33-year-old Perry slammed a 38-ball 40, sharing an unbroken 76-run stand with Richa Ghosh (36 off 28) to take RCB across the finish line in 15 overs.
With the win, RCB finished their league engagements at third position with eight points, while MI (10) stayed at the second spot behind Delhi Capitals (10) in the table.
Needing a win to seal their top-three position, Perry got the ball to nip back from the crease consistently to clean up four batters and trap two in front of the wicket to drain the life out of defending champions, leaving them tottering at 82 for 7 in 13 overs.
Sent in to bat, Hayley Matthews (26) and Sajeevan Sajana (30), who was promoted up the order, provided a blistering start to MI, adding 43 off 35 balls.
Matthew was the aggressor at the start, using her slog shots to blast two fours and two sixes. While Renuka Singh was on the line for Matthews in the third over, Sajana picked Sophie Molineux in the fifth over for special treatment.
However, Sophie Devine ended the powerplay dismissing Matthews, who holed out to Perry as MI were 43 for one in six overs.
Sajana then took over the reins and smashed Devine for a four and a six before Perry brought RCB back into the game.
Perry bowled outside off length deliveries and both Sajana and Harmanpreet Kaur fell for the trap as the ball rattled their stumps to leave MI at 65 for 3 in 9 overs.
Sajana hit five boundaries and a six in her 21-ball knock.
Perry continued to wreak havoc with the ball as she returned to trap Amelia Kerr (2) in front before cleaning up Amanjot Kaur (4) in the 11th over.
Completing her bowling quota of four overs on the trot, the Australian then flattened the off stumps of Pooja Vastrakar (6) first and then deceived Nat Sciver-Brunt (10) with another inward seam delivery in her final over to grab a record six-wicket haul.
It was a sensational show from Perry, who took the six wickets off her last 15 balls. Asha Sobhana (1/12), Molineux (1/26) and Shreyanka Patil (1/3) were also among the wickets.
Priyanka Bala, who replaced Yastika Bhatia in the XI, tried her bit smashing two sixes in her 18-ball 19 before MI folded up for a small total in 19 overs. It was only the second time that MI have been bowled out in WPL.
(With inputs from PTI)