FAS, the watchdog, ruled last September that Google had broken the law by requiring pre-installation of certain applications on mobile devices running on Android, following a complaint by Russia's Yandex.
Google filed an appeal, but FAS said on Monday the court had fully supported its decision.
The company now has to amend its contracts with smartphone manufacturers in order to comply with the ruling, and pay a fine.
Google was last in the news this weekend. South Korean Lee Sedol won his first match against a computer program developed by a Google subsidiary on Sunday in the ancient board game Go, denying a clean sweep for the artificial intelligence in a five-match series.
Lee, one of the world's top players and a holder of 18 international titles, recovered from three consecutive losses against the AlphaGo program developed by DeepMind.
"This win is invaluable and I would not trade it for anything else in the world," a jubilant Lee told reporters after the match, thanking fans for their support.
The 33-year-old professional player has admitted to underestimating AlphaGo's skills but also said the programme was not perfect, asking supporters to keep watching the contest.
DeepMind founder Demis Hassabis told reporters the loss was a valuable learning tool and would help identify weaknesses in the programme that his team needed to address.
© Thomson Reuters 2016
For the latest tech news and reviews, follow Gadgets 360 on X, Facebook, WhatsApp, Threads and Google News. For the latest videos on gadgets and tech, subscribe to our YouTube channel. If you want to know everything about top influencers, follow our in-house Who'sThat360 on Instagram and YouTube.