The visitors were in a strong position, with Yere Goud and Tilak Naidu unbeaten on 38 and 30 respectively when stumps were drawn.
The visitors started their innings on a disastrous note after electing to bat.
Medium pacer Sandip Maniar struck in the second delivery of his over and R Barrigton got an outside edge which wicket keeper Sagar Jogiyani easily accepted and the visitors were one for six.
Uthappa and C Raghu played with caution and added 167 runs for the second wicket.
Both the batsmen had a chance each off the bowling of Medium pacer Sandip Jobanputra before lunch break.
C Raghu was dropped in second slip by Rakesh Dhruve when he had made 28, while Uthappa survived when Firoz Bambhania dropped the catch when he was then on 51.
Rakesh Dhruve sustained injuries while dropping the catch. He developed crack in the index fingure and is out of the match.
At lunch, the visitors were 142 for one and Uthappa was batting on 86. It was the fourth century of Uthappa this season and he has notched highest score in Elite A group.
Before the start of the innings, Uthappa had 723 runs in his kitty and is the super league's top scorer.
Uthappa hit 108 off 109 balls with eighteen fours and one mighty six. He had completed his ton by hitting two fours and a six off Kamlesh Makwana's first over after the lunch break.
C Raghu played an equally good innings and made 83 runs with the help of eleven well executed boundaries while facing 168 balls.
Another worthwhile contribution came from India captain Rahul Dravid. He was out after scoring 56 runs, inclusive of six boundaries. He was bowled by off spinner Kamlesh Makwana.
Karnataka Ist Innings : 329 for 4 wickets in 90 overs (Robin Uthappa 108, C Raghu 83, R Dravid 56, Yere Goud not out 38 Tilak Naidu not out 30 S Jobanputra 1 for 67, S Maniar 1 for 60 and K Makwana 2 for 129).