Gujarat picked up one point from the drawn encounter to take their tally to 24, the same as Madhya Pradesh.
But MP's net run rate (Minus 0.059) was marginally superior to Gujarat's (Minus 0.092) which was enough to pilot the former into the quarter finals along with Mumbai and second-placed Punjab (26 points) from the group.
The knock out quarter finals are to be held from February 3-7, 2016.
But Merai fell for 166, after adding 16 more runs to his last evening's score, and the slim hopes of Gujarat of grabbing the first innings lead vanished.
More From This Section
Merai, who was let off when on 0 yesterday off his own bowling by Shardul Thakur, repaid the compliment and the bowler accepted the catch today to end his marathon 331-minute knock in which he hit 16 fours.
With a handy lead in the bank, Mumbai batted their way to 227 for 6 in their second innings before stumps were drawn for the last time.
Left-handed opener Akhil Herwadkar followed up his first innings 192 with a breezy knock of 41 in 81 balls with six fours while Nikhil Patil remained unbeaten on 44.
For Gujarat, off-spinner Rujul Bhatt grabbed four for 76 after left arm spinner Axar Patel dismissed the two openers to end up with 2 for 85.
Brief scores: Mumbai 531 and 227 for 6 (A Herwadkar 41, S Iyer 37, N Patil not out 44; Axar Patel 2 for 85, Rujul Bhatt 4 for 76) versus Gujarat 421 (P Panchal 36, B Merei 166, R Bhatt 31, Axar Patel 88, R Powar 34; S Thakur 6 for 107, B Alam 2 for 93). Match drawn. Mumbai 3 points. Gujarat 1.