Jimmy White, Mark Selby and Mark Allen were among the big-name casualties on day one of the BetVictor Shoot Out.
White fell at the first hurdle in a 71-39 defeat to Matthew Stevens.
Stevens has enjoyed something of a resurgence in the last couple of years and was firm favourite to progress, though not with the partisan Watford crowd who had waited all day to see the Whirlwind in action.
In the end, Stevens proved too strong, the Welshman in first with a brilliant long red and building a healthy lead before White missed a tricky red along the bottom cushion when given the chance to counter.
White did have time to treat his fans to some trademark pots before Stevens eventually progressed, much to the disappointment of the crowd and Stevens himself.
He said afterwards: "I wanted to miss...for him. But they kept going in."
When asked why he wanted to miss, Stevens replied: "Because I love him. I wanted to Jimmy to win."
Three-time world champion Selby suffered a 54-18 defeat to Sunny Akani in the one-frame format, while Allen lost 54-8 to Luo Honghao following a costly missed black off its spot.
Masters champion Stuart Bingham was edged out 46-41 by Andrew Pagett in Watford, but there were wins for Mark Williams and Kyren Wilson over Luca Brecel and Michael White respectively.
Last year's Shoot Out winner, Thepchaiya Un-Nooh, kicked off Thursday's action with a 63-17 victory over Alex Borg, while David Gilbert booked his place in the next round with a 39-0 win against Robert Milkins.
Malaysia's Rory Thor produced the day's highest break - a superb 133 clearance against Women's World Championship runner-up Nutcharut Wongharuthai - while Chang Bingyu's 120 against 14-year-old Iulian Boiko was the only other century.