Michael van Gerwen, the world No 1, had beer thrown in his face by a fan before his PDC World Championship match against Alan Tabern.
The Dutchman was visibly shocked by the incident and returned backstage to compose himself. Once he returned to the stage he beat his English opponent 3-1 in the second round.
“It has never happened to me before. I did not know how to react, I was so angry,” Van Gerwen said. “The only thing I could do was change my shirt. It was quite difficult and I was quite emotional.”
The 29-year-old Van Gerwen, who won the tournament in 2014 and 2017, averaged 102.59, threw four maximums and had a checkout percentage of 55.
A man was ejected after the incident and banned for life from the championship, officials said.
Earlier Max Hopp reached the third round of the World Championship for the first time with a 3-0 whitewash of Danny Noppert at Alexandra Palace.
The German took advantage of some poor finishing from Noppert to secure a meeting with Van Gerwen.
Noppert, who averaged 97, could hit only three of 22 doubles in the final match of the afternoon session.
Richard North had earlier snatched victory from the jaws of defeat against Robert Marijanovic.
The German appeared to be cruising into the second round, where Steve West awaits, after moving two sets up and leading 2-1 in the third.
But North hit back in emphatic fashion, hitting 10 maximums in a stunning 3-2 win.
The Canadian Jim Long had a debut to remember, beating Mickey Mansell 3-1 to set up a clash with Benito van de Pas, while Josh Payne will face Dave Chisnall after holding on to see off Jeff Smith 3-2.
