Fans reacted with amusement when Iga Swiatek and Jessica Pegula's semi-final clash at the National Bank Canadian Open (Omnium Banque Nationale) in Montreal was bizarrely interrupted by the popular song 'Cotton Eye Joe'.

World No. 1 Swiatek and No. 3 Pegula faced off against each other in a thrilling three-set match in the semi-finals of the WTA 1000 event. The American won the first set before the Polish player came back by winning the tiebreak in the second.

However, it was Pegula that emerged victorious, defeating the four-time Grand Slam champion 6-2, 6-7(4), 6-4.

During the nail-biting tiebreak in the second set, Swiatek served at 3-4 and the two players were caught up in a rally when they were distracted by 'Cotton Eye Joe' suddenly blaring from the speakers.

This caught both women off guard, and the chair umpire decided to call for them to replay the point. Swiatek and Pegula were visibly annoyed by the incident, and the crowd didn't seem too impressed by it either.

Meanwhile, the commentators were able to make light of the situation despite their shock, with one saying:

"Oh wow! ‘Cotton Eye Joe’ just came on, mid-rally. Are we in Texas?"

For those slightly more removed from the immediate situation, it was easier to react with amusement.

"The horrified screams from the crowd are top tier comedy," wrote one Twitter user.

"The audible gasps fom the crowd you would've thought someone was murdered in the crowd," commented another, implying they thought it was a bit of an overreaction.

"This gets better each time I watch it. The element of surprise, the "oh wow" of shock, and the announcer stating the song title as though Cotton Eye Joe is some drunk uncle who showed up as an unwanted guest at a kid's birthday party after repeatedly being told he is not invited," joked another.