With their third win, Mumbai are sitting comfortable at the top of Group C with 12 points, while MP are the fifth place after losing their second match in three games.
Saurashtra, now on third spot after their first win, chased down the target with 19 balls to spare.
Parth Sahani’s 50-ball 90 and debutant Abhishek Bhandari’s 31-ball 54 helped Madhya Pradesh beat Punjab by 34 runs
MP's 35 is the Ranji Trophy's 12th lowest score.
Reddy returned with career-best figures of 6/29 in his 10.5 overs to improve on his previous best of 2/7.
DB Prashanth Kumar top scored with just 29 off 76 deliveries with as many as five players departed to single-digit scores.
The Vidarbha veteran, who recently became the first player to reach 11,000 runs in Ranji Trophy, on Monday appeared in his 146th Ranji match.
With the six points, MP have now toped Group B with 24 points from seven matches, while Himachal are in second place with 22 points.
The 21-year-old Kartikeya picked up six wickets – his career best – to improve on his previous best of 2/56 playing in just his third match.
Shubham Sharma and Puneet Datey were involved in a 61-run partnership for the sixth wicket when stumps were drawn.