The 18-month-long legal battle between the two companies is a rare case of a taxi firm suing a ride-hailing rival over lost revenue.
"Grab requested the Ho Chi Minh City People's Court to reverse the first instance judgment and dismiss the case," Grab said in an emailed statement.
Late last month, the court ordered Singapore-headquartered Grab to pay the sum to Vietnam Sun Corp, better known as VinaSun, which had sought 41.2 billion dong in compensation for what it said were Grab's unfair business practices.
The court found that Grab violated Vietnamese regulations because it operates as a taxi company, and not just as a technology firm.
Grab said on Saturday, however, it does not carry out a transportation business and does not violate local laws.
"VinaSun could not prove its actual damages and/or the causal link between any of Grab's alleged violations and VinaSun's alleged damages," Grab said in the statement.
VinaSun did not immediately respond to a request by Reuters for comment.
(Reporting by Khanh Vu; Editing by Helen Popper)