Uttar Pradesh bounced back after conceding a first innings lead against home favourites Karnataka as their Ranji Trophy quarter-final hung in balance on a day after 21 wickets tumbled here on Tuesday.

On a difficult KSCA pitch, left-arm orthodox spinner Saurabh Kumar (14-4-32-2) relied on his tight bowling to fox Karnataka, which collapsed to 100-8 after taking a healthy 98-run first innings lead.