Right handed Uthappa smashed 116 from only 93 balls as India 'B' comfortably overhauled what at first looked like a competitive target of 261 by India 'A' in the final league encounter of the day-night series.
The teenager's knock, filled with 19 fours and two sixes, put to shade a crafty innings of 110 by international star V V S Laxman who had featured in a tournament-best third wicket stand with Suresh Raina earlier in the day.
Raina became the third batsman in the series to come close to a hundred when he was dismissed on 97 after stitching 187 runs for the third wicket with the stylish batsman from Hyderabad.
But India 'B' did well to strike vital blows in the closing stages to see that India 'A' does not run away to a big total after the Laxman-Raina partnership.
India 'B' needed to achieve the target in 47.3 overs to set up a summit clash with India Seniors tomorrow but Uthappa's blitzkrieg performance made sure they romped home with more than 11 overs to spare.
The victory with a bonus point meant the least favourites of the series finished on top of the tables, above both the Seniors and 'A'.
Uthappa's domineering opening stand of 148 runs with Delhi's Shikhar Dhawan came to an end when the latter was unfortunately run out while backing up too far.
The Karntaka lad began on a cautious note and in fact it was Dhawan, who did the bulk of the scoring in the initial stages. But soon the youngster found his timing and began to go after the bowlers.
He made a mockery of the 'A' bowling that contained India seamer Laxmipathy Balaji, local lad Vikram Rajveer Singh whom his captain had rated one of the fastest in the country and the talented Rudra Pratap Singh.
The bowlers might have found it tough to bowl with the white ball under the floodlit conditions but then Uthappa really caned them.
He cut and drove Balaji four times to the fence and then collected four fours off a R P Singh over.
When Laxman switched to the part-time slow bowling of Raina, Uthappa clubbed him for three fours and a six. He reached the three-figure mark with a four off Manoj Tiwari, reaching the milestone in 78 balls with a six and 17 fours.
After retiring hurt on 107, Uthappa returned to the crease at the fall of his captain Dinesh Mongia (44) and struck two more boundaries before holding out to Jadhav off V R V Singh.
In between, Mongia had added 77 runs with Sridharan Sriram who was unbeaten on 45. India 'B' never really gained from their decision to put 'A' in although they dismissed Dheeraj Jadhav (2) and Gautam Gambhir (10) early.
Only right arm pacer Sreesanth returned with respectable figures of 2-44 but even the Kerala bowler conceded 27 runs in his second spell of five overs.
Laxman and Raina were troubled little by the toothless attack and they dealth primarily in boundaries.
The Hyderabad, after beaten twice outside the off on 99 by Sreesanth, reached his century with an uppish drive through midwicket off Bose.
The right hander then pulled Sreesanth to midwicket fence for two successive fours before, giving himself room and playing an arrogant cover drive, hitting the bowler straight to Ravikant Shukla at cover.
Laxman's 110 came from 121 balls with 12 fours while the left handed Raina faced 124 balls and hit 11 boundaries.
Raina then succumbed to nerves, tyring to loft the leg spin of Piyush Chawla and ending up with a skier that was comfortably held by Parthiv Patel on 97.
Indian 'A' then slumped from 217 for two as six wickets fell for 43 runs, including three of them at 233.
Leg spinner Piyush Chawla and seamer Ranadeb Bose picked two wickets to inflict the damage in the closing stages.