Humphries went two-nil down and looked to be heading for a loss but he showed real resilience to take advantage of Cross's mistakes and loss of form to slay 'Voltage'.
His averages went up every single set with 106, 94 then back up to 101 and finally 102; while Cross dipped from 104 to 93.
He will now have to re-group and prepare ahead of a tie in the evening session on Saturday night against Michael Smith in what is bound to be a high scoring fast paced affair between the pair.
Can 'Cool Hand' have his own Rob Cross story and cap it off on New Years Day or will 'Bully Boy' stop the charge of the Newbury ace?
Click here for more information about the
PDC World Darts Championship, including schedules and the prize fund breakdown.
Evening session schedule Michael Smith (99.72) 4-1 Ryan Searle (96.22) (R4) (3-1, 3-2, 3-0, 2-3, 3-2)
Dave Chisnall (98.5) 4-0 (93.75) Jamie Lewis (R4) (3-2, 3-1, 3-2, 3-1)
Rob Cross (97.38) 2-4 (99.71)
Luke Humphries (R4) (3-0, 3-2, 1-3, 1-3, 1-3, 2-3)
https://twitter.com/OfficialPDC/status/1078782868636061696