World number 26 Holt outplayed last year's runner-up Trump to book a last 16 meeting with Ricky Walden or Martin Gould at the £425,000 ranking event.
After sharing the first two frames, Nottingham's Holt made a break of 115 to take the lead, then crucially won a scrappy 38-minute fourth frame on the colours. He went on to compile runs of 97 and 60 to complete a convincing victory.
"If I'm honest, it doesn't surprise me when I beat anyone," said Holt. "My career has been very disappointing because I want to be a champion but for whatever reason it hasn't happened. Results like this might surprise the public because they never see me play well. I go on television and lose.
"I practise hard and I live well. But when I go under the television lights I don't play as well. If I can get over that then I can be a champion."
Trump said: "Michael played well and deserved to win. I'm very disappointed because I had a good run here last year. It's frustrating to come such a long way and lose in the first round."
Hong Kong's Marco Fu, seeking back-to-back ranking titles having won the Australian Goldfields Open in July, beat Cao Yupeng 5-0 with top breaks of 74, 78, 72 and 78.
Fu said: "Cao gave me a few chances and I took advantage of his mistakes. I felt very comfortable around the table and scored well. I haven't done a lot of solo practice but we are playing a lot of matches. I'm feeling confident and hoping I can keep up the good form. Winning can be a habit. I'd like to get into the top eight by the end of the season."
Peter Lines came from 4-1 down to beat Matthew Stevens 5-4, winning the decider 58-36.
In the wild card round, Andrew Higginson suffered a 5-4 reverse against China's Lin Shuai, who took the deciding frame 48-38.
