On a day where eleven wickets fell, Mumbai gave their opponents an uphill task of scoring 359 runs in 172 minutes and 15 mandatory overs for an outright win and become the second team from Group 'A' to make it to the semi-finals.
Mumbai, with 20 points to their credit had already made it to the last four stage while Punjab with eleven points are in the second position while Railways with ten points are breathing down Punjab's neck.
Mumbai in their last league match take on Punjab from December 25-28 while Railways take on Baroda at Vadodara on same dates in their last league encounter.
Resuming at their overnight second innings score of 82 for three, the hosts progressed quite well with Test discard Vinod Kambli playing a cameo innings of 64 runs off 129 balls including seven fours in the highest partnership of 97 runs with Amol Muzumdar (28 off 118 balls) for the fourth wicket off 37.4 overs.
But once the stylish southpaw was caught by Amit Pagnis off offie Kulmani Parida, Mumbai started losing wickets at regular intervals. Infact the champions lost their last six wickets for just 43 runs off 23 overs and were all out eight minutes after lunch with Parida (three for 39) causing most of the damage.
Another off-spinner Shreyas Khanolkar (three for 19) and J P Yadav (four for 41) were the other wicket takers for the visitors.
Meanwhile in New Delhi, a fine century by opener Rajat Bhatia helped the hosts grab the first innings lead against Kerala and gain two crucial points to stay alive in Elite Group A.
Replying to Kerala's first innings total of 371, Delhi ended the match at 375 for six with Bhatia's 104, compiled in more than six hours with the help of six boundaries and a six, playing a pivotal role.
Delhi now has six points from as many matches and will take on Andhra in an away match in the seventh and final round of the league stage.
Resuming at 108 for no loss, Delhi suffered an early setback when Gautam Gambhir departed for 78, an addition of 17 to his overnight score. Gambhir was caught by C M Deepak off medium-pacer Prashant Chandran.
Vijay Dahiya joined Bhatia and the two took the team total to 204 before Dahiya (36) was dismissed by veteran leg-spinner K N Ananthapadmanapbhan.
Skipper Mithun Manhas then joined Bhatia and the duo added 51 runs for the third wicket. But Kerala succeeded in breaking the stand when Sreekumar Nair clean bowled Manhas (29).
The visitors soon picked up their fourth wicket when Bhatia, caught by Deepak off Sreeshant, departed after his 370 minute vigil at the crease.
However, Kerala's hopes to capture a few more wickets and restrain Delhi did not work out as Ajay Jadeja (60) and Varun Kumar (30) steered them closer to the Kerala's total.
Powar's century puts Mumbai on top
Kerala continues to frustrate Delhi