Kyren Wilson had to be reminded of the protocol ahead of a deciding frame by German Masters opponent Anthony McGill.
Wilson and McGill had been locked at four frames a piece during the pair’s quarter-final clash in Berlin.
With a spot in the last four up for grabs, the two went head-to-head in a deciding frame, but not before Wilson almost broke the handshaking protocol.
McGill was left waiting for Wilson to shake his hand after the reigning world champion appeared to forget about the intended embrace prior to the start of a deciding frame.
Wilson’s faux pas was met with good humour inside the Tempodrom in the German capital, with McGill laughing it off before preparing for his opening break.
Unfortunately for the outsider, he wasn’t able to see off the Englishman, with Wilson keeping his cool to take the final frame and a place in the semi-finals.
It proved a successful end to what had been a difficult evening of work for Wilson, who at one point trailed his Scottish counterpart 3-1 in the race to five.
Despite the adversity, he’s in back-to-back German Masters semi-finals for the first time in his career, with a shot at a second title in this event still alive.
It sets up a clash against Guodong Xiao for Wilson, with the Chinese snooker star having whitewashed Aaron Hill 5-0 in his quarter-final win.
In the other semi-final, Sijun Yuan, who edged a nine-frame thriller against Neil Robertson, will face up against Barry Hawkins.
The Englishman hasn’t won a ranking title since the 2017/18 title, but he admitted ahead of Saturday’s semi-final that he’s feeling confident about ending the drought.
He said: “Even out there tonight, it was almost a full house. The atmosphere is amazing.
“To get through to the one table set-up, after such a long time, is great. I’m really looking forward to it.
“The German fans are probably the best in the world. They are so enthusiastic and clap every shot.”
Hawkings added: “They love the game, so to walk out into that arena tomorrow will be great.
“I’m over the moon. Wu has been one of the players of the season. He is such a devastating long potter. There were hardly any balls missed. To play well and beat him is really pleasing.”
The German Masters victor will take home £100,000, with the final set for Sunday afternoon.