Robertson, a three-time UK champion, recovered from an early lapse to record a controlled 6-1 win over Wu and secure his place in the quarter-finals.
An initial missed black handed Wu the opening frame, but Robertson responded with breaks of 51, 65, 75 and 68 to eventually assume control of the match.
He then overturned a 48-point deficit in the seventh to finish the job, producing the composed, economical snooker that once defined his peak years before last season's slump.
Now restored to world number three and leading the one-year prize-money list, he is beginning to resemble the player who claimed this title in 2013, 2015 and 2020.
Williams suffers upset
Robertson will face Pang Junxu in the last eight, after the world number 30 delivered the result of the session by defeating two-time champion Mark Williams 6-3.
Pang's only previous meeting with Williams had ended in a heavy loss at the 2023 Shanghai Masters, yet he set the tone by taking the opening frame and absorbing Williams's century in the second.
Williams threatened a recovery with a 112 to close to 4-2, and intriguingly had scored more points than Pang at the interval despite trailing 3-1.
That advantage proved cosmetic, as Pang steadied himself with a break of 53 before rounding off victory with a superb 116, earning a standing ovation for a performance built more on clarity of thought than any single flourish.