After being put into bat first, the hosts were in some sort of bother losing half their side for 151 runs off 55.2 overs before Muzumdar faced 207 balls in his 342 minutes stay at the wicket so far with five fours and Powar added 85 runs for the unbroken sixth wicket off 34.4 overs in 139 minutes to steady the rocking boat.
Earlier, Railway's skipper Sanjay Bangar's decision to field first was justified when Mumbai opening batsmen Wasim Jaffer (20) and Pushkaraj Jadhav (6) were back in the pavilion with just 30 runs on the board.
However, Bhavin Thakkar (35 off 113 balls with two fours) and Muzumdar added 62 runs for the third wicket off 26.3 overs in 123 minutes before Thakkar was caught and bowled by medium pacer J P Yadav, who had earlier bowled Jaffer for 20 and had Jadhav caught by wicketkeeper Sudhir Wankhede for six.
Test discard Vinod Kambli (19 off 28 balls) started off well but failed to keep his drive on the ground to be caught and bowled by India all-rounder Sanjay Bangar.
Mumbai skipper Sairaj Bahutule (11 off 37 balls) also failed to give Muzumdar the much needed support and was caught and bowled by offie Shreyas Khanolkar.
Among the Railway bowlers, Yadav bowled a very good line and length to finish with three for 36 while Bangar and Khanolkar took a wicket each conceding 53 and 28 runs respectively.
Munaf, Powar bowl Mumbai to innings win