Russian fifth seed Daniil Medvedev has been fined £7,400 ($9,000) for his behaviour during a US Open third-round win where he was booed by the crowd.

Medvedev, 23, was fined £4,100 ($5,000) for unsportsmanlike conduct and £3,300 ($4,000) for a visible obscenity.

He snatched a towel from a ball person and then made an offensive gesture to the fans on Arthur Ashe Stadium.

After beating Spain's Feliciano Lopez, Medvedev thanked the crowd for giving him "the energy to win".

The world number five received an unsportsmanlike conduct code violation for snatching a towel in the first set and later put his middle finger up on the side of his head.

He escaped punishment for the gesture because it was unseen by umpire Damien Dumusois but was later replayed on a television screen in the stadium.

Medvedev was also booed while he was interviewed on court after the match, and said: "I want all of you to know, when you sleep tonight, I won because of you. The energy you gave. The more you do this, the more I win."

Medvedev faces German qualifier Dominik Koepfer next and said he would try to improve his behaviour.

"I am working on myself and hopefully I will be better next time," the Russian added.