Michelle Williams has split with boyfriend Jason Segal.

Sources tell US Weekly that it was the distance that doomed William's first public relationship since Heath Ledger.

Williams lives in Brooklyn with Matilda, the 7-year-old daughter she had with Ledger and Segel lives in Los Angeles, where he shoots the CBS sitcom "How I Met Your Mother."

The split reportedly happened earlier this month.

Segal was quite taken with Michelle's daughter, a source told US in June. Back then, the couple's future looked bright.

"[Williams and Segel are] "totally in love," the source said. "Jason is obsessed with Michelle."

The couple never opened up to the press about their relationship. Yet, Segel vaguely confirmed its existence to Extra back in April.

"I think we would just very much like to be happy," Segel said. "That's all I'm going to say about it."

But if Williams was torn up about the split, she didn't let on at a promotional event for "Oz: The Great And Powerful" in Moscow, Russia with Mila Kunis and James Franco.

Michelle posed for photos and answered questions with all of the grace you could ask for from a movie star.

Yet according to an inside source, both Williams and Segel are depressed about the split.

"The breakup was mutual," said the source. "It's a sad moment. They respect each other."

"They had a lot of fun, but it just didn't work," a friend of the couple said.