A federal judge ruled Monday that Google unlawfully sustained its monopoly in online search and advertising market, citing Google’s payments made to companies to secure prime placements on smartphones and web browsers violated US antitrust laws.

Google’s $26 billion in payments to companies such as Apple in 2021 to ensure its search engine was the default on browsers and mobile devices were found to effectively block competitors from entering the market, ruled Judge Amit Mehta.

Mehta’s decision is a significant victory for the Department of Justice, marking the first antitrust trial in over two decades involving a US technology company.

In his ruling, Mehta declared, “Google is a monopolist, and it has acted as one to maintain its monopoly,” citing violations of Section 2 of the Sherman Act.

Google said it will appeal the decision and that the judge’s ruling affirmed its argument of having the best search engine.

Google’s position as the default search engine on Apple’s Safari browser—a reportedly $10 billion partnership dating back to the browser’s launch in 2003—has drawn more users to its search service, significantly bolstering its ad revenue. According to Statista, Google’s search operations generated over $300 billion in annual revenue last year.

The trial commenced last fall and lasted 10 weeks, featured testimony from prominent figures in Silicon Valley, including Google parent company Alphabet CEO Sundar Pichai, Microsoft CEO Satya Nadella and Apple executive Eddy Cue.

Throughout the proceedings, Google has maintained its stance against any allegations of anticompetitive behavior, and that its large market share is a result of a superior product enjoyed by consumers.

Google is set to face another antitrust trial on Sept. 9, this time focused on its adtech practices. The DOJ has alleged that Google has illegally preserved its dominance in the digital advertising market, allegedly boosting its revenue while raising costs for advertisers.