The tyro top-scored with 57 off 37 balls as Royals, who failed to complete the chase in eight of their nine games this season, reached 4-188 with 17 balls to spare.
The match was a dead rubber with both teams already eliminated from play-off contention.
Fast bowler Akash Madhwal (3-29) was effective with his reverse swing in the final overs to restrict Chennai to 8-187 and allow Mahendra Singh Dhoni's team to add only 17 runs in the last three overs.
The win lifted Rajasthan off the bottom of the table and Chennai now need a huge win against table-topping Gujarat Titans in their final league match to avoid finishing last for the first time in their IPL history.
Earlier it was revealed Ahmedabad will host the June 3 final following the enforced revision of the schedule due to the suspension caused by armed conflict between India and Pakistan.
The city's huge Narendra Modi Stadium will also host qualifier two on June 1. The first qualifier (May 29) and the eliminator (May 30) will be held at the New PCA Stadium, New Chandigarh.
The venue hosted the final in 2022 and 2023, attracting more than 100,000 on both occasions.
The play-offs, initially slated for Hyderabad and Kolkata, have been relocated due to adverse weather conditions in southern India.
The IPL was halted on May 9 and resumed on Saturday following a ceasefire. However, the restart match between Royal Challengers Bengaluru and Kolkata Knight Riders was abandoned due to rain without a ball being bowled.
RCB's final home fixture against Sunrisers Hyderabad (SRH) has been moved to Lucknow where they will also play their final away game against Lucknow Super Giants.
with AP
