Mark Allen edged to a 5-4 lead over defending champion Neil Robertson after an enthralling opening session of the 888sport Champion of Champions final in Milton Keynes.
The clash is a repeat of the 2015 Champion of Champions final, which saw Robertson emerge a 10-5 victor. However, the Australian will have to come from behind to secure the title this year.
The high quality afternoon session saw both players produce a barrage of breaks. Northern Irishman Allen opened proceedings with a contribution of 101, before Robertson replied immediately with a fine run of 121 to draw level at 1-1. Allen then claimed the following two frames to head into the mid-session 3-1 ahead.
Robertson pulled within a frame upon the resumption, before Allen restored his two-frame cushion with a break of 110. However, Robertson produced back-to-back century runs of 108 and 109 to restore parity at 4-4. Allen then took the last of the afternoon to secure his one frame advantage.
They will return at 7pm to play the best of 19 encounter to a finish, with the winner picking up the £150,000 top prize.