Jordan Brown is continuing his remarkable run of form at the Welsh Open as he leads Ronnie O’Sullivan 5-3 after the first session at Celtic Manor.
The world number 81 is in with a chance of becoming the lowest-ranked winner of a ranking event since 1993 if he can beat the Rocket in the race to nine frames.
Breaks of 107, 78 and 58 from Brown have helped him on his way, but it is not as though O’Sullivan is playing poorly and the underdog is capitalising.
The world champion has made breaks of 135. 121 and 74 himself and will be surprised to be trailing to the man playing in his first ranking event final.
An 8/1 underdog with the bookmakers coming into the match, Brown settled down quickly, taking the first frame, in which both men had chances.
The Northern Irishman then began to properly find his rhythm, making a break of 58 in the second to go 2-0 ahead.
O’Sullivan responded with a 74 in the third, but Brown was anything but rattled and showed some serious quality with a 78 and 107 in the next two frames, taking a shock 4-1 lead.
The Rocket had not scored a point in either the fourth or fifth frame but the world champion is not brushed aside so easily and he returned to knock in back-to-back centuries of 135 and 121 to return to within one frame.
The final frame of the first session felt huge as both had good chances in the balls to claim it and if the Rocket had gone in level then he would be overwhelming favourite, but it was Brown that pinched it.
Many will still fancy the world champion to push on to victory even from 5-3 down, but Brown is playing superbly and put himself in an excellent position.
The two men return to the table at Celtic Manor at 7pm on Sunday to complete their race to nine frames.
For more stories like this, check our sport page.