In pursuit of Mumbai's massive 570 all out, Railways were trailing by 190 runs at stumps, and required another 41 to avoid follow-on.
To challenge the might of Mumbai, the visitors needed at least a couple of big knocks from their top-order batsmen but that did not happen, though there were three half-centuries.
Railways, however, could not really capitalise on the lives they got at the Wankhede stadium.
Ashish Yadav was dropped on 12 by wicketkeeper Aditya Tare off Romesh Powar. Yadav went on to make 47 off 120 balls with the help of six boundaries, but that was not enough considering the situation.
He forged a 77-run partnership with Murli Kartik, who chipped in with 41.
Both the batsmen were caught by Sachin Tendulkar off bowler Iqbal Abdulla.
More From This Section
Senior pacer Zaheer Khan, who started the day's proceedings, left mid-way during one of his overs due to cramps.
"It's a cramp, and hopefully, he should be back tomorrow morning. We didn't want to exert him too much (today)," the Mumbai team manager said.
Centurion Abhishek Nayar had to step in to bowl Zaheer's last delivery. It was the 99th over of the match and the pacer's 12th of the day.
The veteran bowler, in his third spell of the day, took the wicket of Mahesh Rawat, who was caught behind. It was Zaheer's third over, after opting to take the new ball after the mandatory 80 overs. More