Mayank Agarwal's maiden double-hundred and R Samarth's seventh century cemented Karnataka's command over Maharashtra in Pune. They added 259 for the opening stand, which paved the way for the visitors extending their lead to 216 by stumps on the second day.
Samarth hit 129 off 219 balls - his second hundred in three matches - before part-time offspinner Swapnil Gugale had him caught behind. Agarwal, though, went to stumps not out on 219 off 373 balls, including 25 fours and two sixes. He made a rousing return to form after having bagged a pair against Hyderabad last week.
Debutant Dega Nishal (16) was the only other batsman to fall on the day. Agarwal and Karun Nair (56*) added an unbroken 151 to take the score to 461 for 2 before stumps.
Hyderabad captain Ambati Rayudu struck his first hundred since returning to the state, and fast bowler T Ravi Teja struck a 63-ball 70 on debut to propel the score to 474 for 9 declared against Railways at the Karnail Singh Stadium in Delhi. Ravi Teja then bowled opener Saurabh Wakaskar for 5 to cap a memorable day.
Rayudu added 24 to his overnight score of 88 before being dismissed by seamer Amit Mishra in the 101st over. B Sandeep, the other overnight batsman, was also dismissed early as the visitors slumped to 319 for 5 from an overnight 272 for 3. Debutant K Rohit Rayudu then perished soon after lunch to give Railways a way back at 353 for 6.
But the left-handed Ravi Teja was aggressive in his 47-run stand with Akash Bhandari (40). He struck at over 100 in a 53-run stand for the eight wicket that took Hyderabad to 453, before they declared on 474.
Ravi Teja was to form one final partnership on the day, this time with the ball, as he and fast bowler Ravi Kiran attacked Railways' left-handed openers from around the wicket. The tension drew a wicket, that of Wakaskar, who played onto his stumps. Shivakant Shukla and Nitin Bhille survived a nervy battle in the fading light to take Railways to stumps without further damage. They trail by 439 runs with nine wickets in hand.