The Six Nations is on average attended by more people than any other sport in the world, according to a new UEFA report.
It is one of rugby's flagship events each year and attracts an average supporter base of 72,000.
In 2015, the tournament, which brings together England, Scotland, Ireland, Wales, France and Italy over 15 games, saw just over one million fans attend stadia such as Twickenham, the Millennium Stadium and Murrayfield.
The competition saw England and Ireland scrap it out for the title, with Ireland emerging victorious to claim their 13th trophy win.
The fact that it remained so tight until the last fixtures meant numbers were boosted.
NFL - which is now viewed more than ever before in Britain, given its introduction to Wembley - ranks second.
Nearly 18 million fans turned in total turned out for the 2015 season, which spanned across 256 games.
Sixty-four thousand on average turned up throughout the campaign, which included a Super Bowl victory for the Denver Broncos at the Levi's Stadium. In total 71,088 packed into the Levi's Stadium in Santa Clara, California.
The 2014 World Cup in Brazil rounds off the top three. Given its location in South America, football's biggest tournament wasn't attended by as many, particularly those supporters from Europe.
Just under 3.5m did attend the tournament and on average 53,592 made it to the 64 matches.
The final, which was won by Germany over Argentina, drew a crowd of 74,738 inside the Maracana.
And UEFA's licensing benchmarking report, which Sportsmail has seen exclusively, reinforces the view that football remains the most popular sport on the planet.
It accounts for 10 of the 20 most attended sports events, with the recent European Championship in France ranking fifth overall. The Premier League ranks 10th - three places behind the Bundesliga for the 2015-16 season.
'Given its status as the "global game", it is not surprising that football accounts for more than half (29) of the 50 most highly attended global sports leagues and events,' the report adds.