The two leaders said it was a setback for those who sought to break the AIADMK and topple the government.
Palaniswami played down murmurs of discontent in party ranks, saying it was a work of media which "magnified" it.
"The EC ruling has come as a body blow to some persons who thought of breaking the party and topple the government," Palaniswami said without naming Dhinakaran.
Deputy chief minister O Panneerselvam said people and cadres will not accept those who were bent on toppling the government ushered in by "Amma," adding the verdict had given a body blow to such forces.
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To a question on Dhinakaran hitting out at the ruling party, he said only the EC has the authority to decide the matter and not the sidelined party deputy general secretary.
Palaniswami said party cadres and people were happy about the outcome to the poll symbol row, and added that the ruling showed that only "dharma will win."
Addressing a crowded press conference at the party headquarters here, the chief minister said "God has given a good verdict."
He said the verdict was against those who joined hands with opposition parties and conspired against his faction and government.
The reference was apparently aimed at the Dhinakaran-led faction.
To a question on discontent in party ranks, Palaniswami said "only the press and media is magnifying it."
He said ruling party leaders were sitting together and held unanimous view and asked TV channels to show to the people and cadres "without editing" how happy they were.
Significantly, Rajya Sabha MP V Maithreyan, who raised the discontent row, was seated in the front row alongside other leaders including party presidium chairman E Madhusudanan and Panneerselvam.
Besides Madhusudanan, another Panneerselvam loyalist, former Minister K P Munusamy was also seated near the chief minister.
Earlier, Palaniswami, Panneerselvam and other ministers distributed sweets to party workers and journalists at the party office.
The party cadres celebrated the verdict by bursting crackers and distributing sweets across the state.