"Kyle Busch is an a**": When Brad Keselowski publicly chastised his fierce NASCAR rival in front of over 150,000 spectators

Kyle Busch and Brad Keselowski birthed one of the fiercest rivalries in NASCAR. The duo had multiple run-ins throughout their careers, but the seed of their feud was sown at the 2010 Xfinity Series race hosted by the Bristol Motor Speedway. In the aftermath, Keselowski publicly castigated Busch in front of over 150,000 fans during driver introductions.

Busch kicked off his Food City 250 from third place in his #18 Toyota while Keselowski began in 13th. However, as the 250-lap battle inched closer to its conclusion, the then-Penske Racing driver held the domination while the former #18 Joe Gibbs Racing driver fought hard for the lead.

After struggling to overtake for nearly a dozen laps, Busch, with 31 laps until the checkered flag dropped, lunged ahead of Keselowski, only to be wrecked from behind and lose the spot again. However, the JGR driver quickly retaliated and spun out Keselowski's #22 Dodge. The move propelled the #18 Toyota to the victory lane while the Penske driver fell from a potential win to settling in 14th place.

The bitter feeling inside Brad Keselowski surfaced during the Bristol Cup Series race driver introductions the following day. After Kyle Busch introduced himself, his fierce rival took the mic and blasted Busch with his "a**' comment.

"Brad Keselowski, driver of the Penske Racing Dodge. Kyle Busch is an a**," he said.

However, when asked why he slammed Busch, Keselowski said that Juan Pablo Montoya challenged that he can't call the JGR driver an "a**". It's worth mentioning that the crowd's roar on the Penske driver's introduction notched 104.2 decibels.

"Sometimes you just don’t like a guy": Kyle Busch publicly slams Brad Keselowski during their 2017 title fight

The bitter rivalry between Kyle Busch and Brad Keselowski was such that both made unapologetic comments about the other from time to time. Despite the latter publicly extending an olive branch to the former in 2015, their relationship remained sour.

The 2017 Championship 4 race saw Keselowski, Busch, Martin Truex Jr., and Kevin Harvick fight for the highly-coveted Cup Series title. Keselowski and Busch already had a championship in their arsenal and were set to fight for another title. However, it was Martin Truex Jr. who upset his rivals to register his maiden Cup Series crown.

But during a pre-race presser, Busch commented on his long-running rivalry with Keselowski and said.

“Sometimes you just don’t like a guy — fact of the matter. I never ran into Matt Kenseth; I don’t think Matt Kenseth ever ran into me, so there is a respect factor out there on the race track and you certainly do a better job sometimes when you’re around some of those guys that you may or may not necessarily like, but as once a wise man told me, I think it was Chase Elliott, I race those like they race me," Busch said via NASCAR.

Kyle Busch was successful in his pursuit of outperforming Brad Keselowski. With five wins, 14 top-5s, and 22 top-10s, the JGR driver settled his 2017 season in P2, while with three wins, 15 top-5s, and 21 top-10s, the Team Penske driver stood fourth.