Five-time champion Ronnie O'Sullivan and China's 2016 world finalist Ding Junhui will enter the final session of their second round world championships clash tied at 8-8 after honours were shared on Saturday. The pair began the second session at 4-4 but Ding opened up a 7-5 frames lead in the best of 25 clash including two century breaks. O'Sullivan -- who has not reached the last four at the championships since losing to Mark Selby in the 2014 final -- came back strongly. He went 8-7 up by winning three frames in just over half-an-hour only for Ding to level the session and the match with the final frame. Whoever comes out on top in Sunday's session plays three-time world champion Mark Williams in the last eight. pi/td