Barry Hawkins finished Sunday's evening session at the World Championship locked at 8-8 with two-time Crucible runner-up Matthew Stevens.
In an absorbing morning session 32-year-old Dartford man Hawkins gained an early 3-0 lead, maintaining the form which saw him made no mistake against an injured Selby in the first round.
Qualifier Hawkins was pegged back to 3-3 and then ground out a long frame before regaining fluency to pull two frames clear going into the evening.
Hawkins held his nerve in a gruelling 47-minute frame to restore his lead, before a 65 gave him the cushion to take into Sunday evening's middle session.
But Stevens scored heavily at times firing in three century breaks, 101, 122 and 123.
However Hawkins led for much of the way and by the end of their second session the pair were tied at 8-8, with Stevens needing an 80 break in the final frame to restore parity.
On the other table, Neath's Jamie Jones moved 10-6 ahead of Andrew Higginson in a battle of the qualifiers.
Jones finished with a tidy 72, the highest break by either man, as the morning session ended 4-4, but the Welshman surged ahead with breaks of 95 and 101, plus a gutsy clearance of 39 to pinch the final frame, doubling in the black to open up his four-frame lead.