Skipper Mayank Agarwal hit a double century to help Karnataka post 407 in their first innings and take the upper hand over Saurashtra in their Ranji Trophy semi-final here on Thursday.

Resuming his innings at 110, Agarwal carried on his good form and played with more intent on the second day to score 249 off 429 balls. He struck an astounding 28 boundaries and six sixes during his marathon knock.