The Twilight actress, who split from Joe Jonas last week, was allegedly seen "dancing closely" to Evans.
An insider told E! News: "Ashley was all over Chris, and he certainly didn't mind.
"They were dancing together very closely. It looked like they had a lot of sexual chemistry."
However, Greene's friends have insisted that the 24-year-old is just having fun. A friend said: "Ashley is newly single. She's hot, of course she's going to be out having fun."
Since splitting from Jonas, the actress has also been linked to Kings of Leon star Jared Followill after being spotted with him twice last week.
The pair were reportedly "flirting" at New York nightclub Avenue last week. An onlooker commented at the time: "Ashley was smiling all night. She and Jared were close the whole night. Dancing, talking, flirting. It was pretty clear they were into each other."
They were then seen again on Thursday where they celebrated St Patrick's Day together at Phebe's Tavern & Grill in New York.
Greene later tweeted: "Good food. Good friends. Great day."