O'Sullivan booked in his place in the quarter-finals with a typically rapid 4-2 victory over fellow speedster Thepchaiya Un-Nooh while Trump got the better of Martin Gould in a match in which the 4-1 scoreline probably flattered the world number one.
O'Sullivan needed just over an hour to see off Thepchaiya but the latter was left to rue a crucial missed red to the middle pocket in frame five when on 66 and only a couple of pots away from leading 3-2.
Sensing his moment, O'Sullivan stepped in with a trademark clearance of 70 that was highlighted by a brilliant cannon to free a safe red on the right-hand side cushion before taking care of the colours in ruthless fashion.
With that body blow still stinging, Thepchaiya wasn't able to hit straight back and O'Sullivan closed out the match with a run of 52 to go with his earlier 50+ contributions of 60, 70 and 106.
Earlier in the day, O'Sullivan came through a scrappy match with Matthew Stevens in the last 32 after Trump had been given an almighty scare by Luca Brecel.
Brecel twice led to put himself within touching distance of the winning line but the Belgian was guilty of a number of crucial unforced errors that allowed Trump to claim the final two frames and edge through.
A few hours later, the defending champion looked in much better shape as he pulled away from Gould thanks to breaks of 52, 103 and 76 after turning the match on its head when winning the second frame on a re-spotted black.
Trump will play Scott Donaldson in the last eight after the latter saw off Noppon Saengkham 4-2 while Ali Carter and Kurt Maflin will face each other following wins over Ben Woollaston and Igor Figueiredo respectively.
Former UK Championship semi-finalist David Grace came through another final-frame decider as he edged out Michael Holt 4-3.
Holt had raced into a 3-0 lead with breaks of 76, 66 and 75 but Grace responded in kind with contributions of 64, 62 and 58 to win a high quality-encounter.
Next up for Grace is Yan Bingtao who just outlasted Zhao Xintong in another match that went the distance.
The final match on Thursday saw Ding Junhui ease past John Higgins 4-1 to secure a quarter-final with O'Sullivan on Friday evening.
