The Canadian National Anthem was booed at Yankee Stadium before New York's playoff clash with the Blue Jays - sparking fury among some baseball fans.
The Blue Jays and Yankees clashed in Game 3 of the American League Division Series on Tuesday night, with Toronto leading 2-0.
Yankees supporters were branded 'classless' and 'pathetic' after footage showed the rendition of 'O Canada' being drowned out by boos.
'Classless. You didn’t see Canadians doing it during this series,' one fan said on social media. 'I thought Toronto and NY were friends. Now we’re enemies,' wrote another.
A third fan called the Yankees supporters 'pathetic' while a fourth added: 'Classless f****. Wouldn’t expect anything less.'
Some fans inside Yankee Stadium tried - and failed - to mask the boos with cheers. And when Graham Rowat finished 'O Canada,' chants of 'U-S-A, U-S-A' could be heard.
Vladimir Guerrero Jr. shushes the crowd after scoring a homer against the Yankees on Tuesday
New York is looking to stay alive in the best-of-five American League Division Series
The Yankees are looking to stay alive in the best-of-five series but - despite the hostile reception - the Blue Jays made an ominous start to Tuesday night's game.
Toronto raced into a two-run lead in the first inning, with the Yankees responding with an early run of their own.
On Monday night, meanwhile, former President Joe Biden was spotted supporting the Philadelphia Phillies in the MLB playoffs.
Biden, 82, and former First Lady, Dr. Jill Biden, 74, made a surprise appearance at Citizens Bank Park to watch the Phillies take on the reigning champions, the Los Angeles Dodgers, in Game 2 of the National League Division Series.
And the couple, whose primary residence is in Greenville, Delaware, just a 40-minute drive from South Philadelphia, almost witnessed a thrilling comeback.
The Bidens' beloved Phillies were trailing 4-1 in the bottom of the ninth before they staged a late comeback. The Dodgers managed to hold on for a narrow 4-3 win, leaving Philadelphia staring down the barrel of elimination in the best-of-five series.