Was Serena Williams' pep talk key to Dimitrov's US Open win?

Could Serena Williams have been key to Grigor Dimitrov’s fourth-round victory at the US Open against Andrey Rublev?

The 2017 Nitto ATP Finals champion revealed that he spoke to the six-time US Open singles champion on Saturday before triumphing in five sets on Sunday. The 33-year-old also discussed to what extent he gets nervous playing in front of his longtime friend.

“For some reason not in front of her,” Dimitrov said. “She gave me a good pep talk yesterday. Yep, I know, exactly. I’m thrilled.”

? That's what friends are for ?@serenawilliams ?? @GrigorDimitrov @usopen | #USOpen pic.twitter.com/lePW8PPeh8

Williams was watching from a suite alongside American singer Alicia Keys.

“It’s amazing honestly to play in front of you guys, in front of good friends and family,” Dimitrov said. “All in all it’s a tremendous atmosphere so again thank you all. Thank you so much for the support.”

Dimitrov will play Alexei Popyrin or Frances Tiafoe for a place in the semi-finals at Flushing Meadows.

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