The Welshman was a last minute replacement for Chinese talent Zhao Xintong after the youngster tested positive for Covid-19 leaving a space empty in the eight-player tournament. Three-time world champion Williams answered the plea by organisers and took the 13-hour flight arriving just hours before his quarter-final match against Australian Neil Robertson.
Williams spent an hour at his hotel before leaving for the match, unsurprising lost 5-3 but picked up a £22,500 participation fee in the process.
"I knew I couldn't win today, I'm knackered" said world number eight Williams talking to Eurosport. "Anybody who follows me on Twitter knew I couldn't win today.
"All I came for was the £22,500. I'm going to be honest. I've had about two hours sleep in two days. I didn't arrive in my hotel room until about 10.45am and I was picked up at 11.45am to come down here to play my match.
"I tried my best and somehow I got three frames off him. It was strange, but if it wasn't for that prize money, I wouldn't have come."
The Welshman didn't have the easiest trip either after his Covid-19 test on departure from Heathrow Airport was "inconclusive". After being allowed to depart he then tested negative in Hong Kong, but still had to wait an hour for his cue to come off the plain.
Playing in front of a huge crowd in the 12,500-capacity Hong Kong Coliseum, Williams starting the match with an impressive break of 133 and winning further frames of 80 and 55.
However, he couldn't prevent Robertson from progressing into the semi-final.
Williams added: "I had plenty of chances, but kept missing easy balls. I had a couple of breaks which I wasn’t expecting.
"It was just nice to play in this arena, I might not play here again, I don’t know. It’s some arena, absolutely massive and I’m glad I’ve done it at least once."