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O'Sullivan won a final-frame decider against the Scot after he had trailed 4-1, while Trump beat Shaun Murphy 5-3 in their last-eight clash.
'The Rocket' (pictured) took a 2-0 lead in the best-of-nine clash before Higgins got on the scoreboard thanks to a break of 87.
He then won three frames in a row thanks to runs of 72, 61 and 81 only for O'Sullivan to delight his army of fans in Hong Kong by winning the last three frames to pull off an impressive comeback.
"I felt I got away with that one, I was 4-2 down and John was playing solid," O’Sullivan told worldsnooker.com.
"I won a good frame to go 4-3 and that put the match in the balance. You should never give in until it’s over. For my first match since the World Championship I felt pretty good. I enjoyed the occasion, it was a great crowd and you have to look forward to playing in an atmosphere like that."
Higgins said: "I had a few chances and didn’t take them and that came back to bite me. We missed a few easy balls between us tonight. All the players are a bit rusty and my technique was all over the place in some frames."
Earlier, world number three Trump had stormed into a 3-0 lead, helped by breaks of 83 and 100 in the opening two frames, before Murphy finally got off the mark with a run of 53.
The next two frames were shared before Murphy reduced the the deficit with a break of 76 but his fightback was in vain as Trump's run of 92 in the eighth sealed an impressive victory.
He told worldsnooker.com: "I played ok, I missed a few chances when among the balls. This is one of the first tournaments of the season so everyone is a bit rusty. It was important for me to get a good start. Shaun made some good breaks to get to 4-3 so I was happy to make a break in the last frame.
"The arena is very big and the fans were good, we feel very welcome here. Marco Fu will be the man to beat this week because of the support he gets."
Yesterday's games saw Neil Robertson knock out world champion Mark Selby and Marco Fu defeat Barry Hawkins.
The sold-out eight-man invitiational tournament, with £315,000 worth of prize money up for grabs, has been organised as part of the celebrations for the 20th anniversary of the establishment of the Hong Kong Special Administrative Region.
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