Brussels set the penalty in 2018 over allegations the firm used its Android operating system to thwart rivals.
It says Google forced phone makers to install its search engine and other tools.
In court on Monday (September 27) Google rejected the allegation, calling its software a success story of competition at work.
It also hit out at officials for overlooking Apple.
Google said the EU ignored the power of its Silicon Valley rival, and wrongly concluded that Android enjoyed dominance in operating systems.
The European Commission rejected that argument, saying Apple's market share was small compared to Google's.
Android is found on about 80% of the world's smartphones.