Mao, like Tito, had led a revolution against feudalism and to unite his country. But, like Tito, he was not much of a Marxist. In power he was a nationalist more than anything. In the 1940s and much of the 50s his theoretical views justified policies that were clearly at variance with Marxism, such as the view that the bourgeoisie and proletariat could assume "non-antagonistic" relations with each other under New Democracy.
After Stalin's death the Soviet revisionists began pandering to nationalist elements inside the socialist camp, as signified by their rehabilitation of Tito (a move Mao himself fully supported.) But the revisionists, unlike Mao, were not interested in turning China into a world power and giving it nuclear weaponry.
In response the Chinese began to oppose the Soviets from what seemed like leftist positions. This would especially gain them followers among the third world countries who were opposed to the USSR's rapprochement with American imperialism and Khrushchev's calls for "peaceful coexistence" which essentially told those in colonies and semi-colonies to cease fighting for national independence.
By the beginning of the 1970s the anti-Marxist nature of Maoism was revealed internationally; Mao met with Nixon and openly aligned China with US imperialism. The "left" positions China took against the USSR were shown to have been demagogy. In the course of the 1970s the Chinese praised Tito and upheld the likes of Mobutu, the Shah of Iran and Pinochet as anti-imperialists.
In conclusion, the Sino-Soviet split reflected the interests of two powerful revisionist, state-capitalist countries, one emergent and the other already in a supreme position.