Ashlee Simpson Backless Dress Praised by Fans (VIDEO)

Ashlee Simpson attended this year's ballet opening gala wearing a stunning black gown in New York City on Monday.

The 2013 American Ballet Theatre Opening Night Spring Gala saw several high-profile guests, but it was Jessica Simpson's little sister who stole the spotlight.

The 28-year-old wore an elaborately decorated long black frock that featured a lace collar and cutout back which earned her praise from fashion critics.

Moreover, the Alive + Olivia dress featured a feather peplum accent. Simpson paired the gown with bright emerald earrings. and her blonde hair loosely curled and worn up. Watch a video featuring the actress' gala appearance on YouTube

The actress' glamorous look made waves on social media sites.

"BEST look hands down," wrote Alex.

Twitter user Danielle went as far as saying Monday was the best Simpson has ever looked.

"OBSESSED with this dress. OBSESSED with this look," she wrote. "Well, this is the best Ashley Simpson has ever looked, huh?"

"We almost didn't recognize @ashleesimpson in this photo," People magazine posted to the micro blogging site. "What do you think of the dramatic dress? (We're into it!)"

Simpson was not the only star to wear a dramatic look during the NYC event. Among them were Coco Rocha and Lucy Liu, who both wore long gowns.

Simpson is the mother of 4-year-old son Bronx, whom she shares with ex-husband and Fall Out Boy bassist Pete Wentz.

Despite the end of their marriage, Simpson and Wentz have been able to put aside their differences in order to be parents to Bronx.

"I feel like we both realize that we're parents and we're in it for our kid," said Wentz during an appearance on "Watch What Happens Live."

"That's made it really easy," the musician added.

Sometime in the near future, Simpson will become an aunt for the second time when her sister Jessica welcomes her second child.