When Márquez arrived in MotoGP in 2013, he openly acknowledged Rossi as his childhood idol and expressed pride at competing against him. Their early encounters on track were typically hard but without lasting animosity. At the 2015 Argentine Grand Prix, Márquez retired from a collision with Rossi and both riders treated it as a normal racing incident. A similar contact at Assen that year was handled comparably. The relationship still appeared functional, if competitive.
The rupture began to accelerate at the 2015 Australian Grand Prix. Rossi publicly accused Márquez of deliberately racing aggressively against him in Australia in a manner designed to assist Rossi's Yamaha teammate and championship rival Jorge Lorenzo — who was chasing Rossi in the standings. Both Márquez and his team denied the accusation.
The crisis reached its decisive moment at the penultimate round in Malaysia. Rossi and Márquez were engaged in a three-lap battle for third place, trading positions multiple times per lap. On lap seven, at turn fourteen, the two collided: Márquez fell from his bike and eventually retired in the pit lane after remounting. Rossi continued and finished third. During the duel, Rossi was seen making contact with Márquez's leg — a moment that race direction and subsequent investigation treated as a contributory cause of the crash.
Race direction imposed three championship penalty points on Rossi for the incident. Combined with a penalty point he had received earlier in the season, Rossi was required to start from the rear of the grid at the championship-deciding final round at the Valencian Community. Rossi launched an appeal to the Court of Arbitration for Sport but withdrew it in December 2015 without further contest.
At Valencia, Lorenzo won the race and Rossi recovered from the back of the grid to fourth. Lorenzo clinched the championship by five points. Rossi called the title a "Spanish stitch-up" and stated that "having Marc Márquez as the bodyguard of Lorenzo is embarrassing" — accusing Márquez of deliberately defending Lorenzo against both Pedrosa and Rossi in the final laps rather than racing for his own result. Márquez and his team denied the accusation.
Three years later, at the Argentine Grand Prix in 2018, the relationship flared again. Márquez collided with Rossi, who retired from the race. Race direction penalized Márquez with a 30-second penalty for the incident. Rossi refused to accept Márquez's post-race apology, and a member of the Rossi garage asked Márquez to leave.
In the aftermath, Rossi stated that Márquez "destroyed our sport" with his aggressive riding and that Márquez needed to stay away from him. At the San Marino race later that season, Rossi again declined to shake Márquez's hand, saying there was no problem between them but no handshake was needed. By the following year's Argentine Grand Prix in 2019, the two did shake hands before the podium ceremony.
The rivalry differed from Rossi's previous great rivalries — with Biaggi, Gibernau, Stoner, and Lorenzo — in its specifically political dimension. What made the Márquez confrontation uniquely damaging was Rossi's sustained belief that Márquez had functioned as an agent of a Spanish sporting interest group rather than a neutral competitor, and his willingness to say so in public. These were the most serious accusations made by any major rider about another in the modern era.
Márquez denied all such characterizations throughout. He became the dominant champion of the 2010s, winning six MotoGP titles between 2013 and 2019 (missing 2015 and 2017), and his technical excellence was widely recognized even by those sympathetic to Rossi's position. The collision that triggered the 2015 penalty — and the broader relationship between the two riders — remained a reference point in MotoGP discussions about racing ethics, nationalism, and championship politics for years afterward.
Rossi retired from MotoGP at the end of the 2021 season. Márquez, after an extended recovery from his 2020 arm injury and subsequent surgeries, continued racing into the mid-2020s. The events of 2015 in particular — the Malaysian contact, the penalty, the Valencia grid start, the five-point margin — are cited among the defining controversies of the sport's modern era.