Nector Marmolejos / WENN 1 / 6
Nector Marmolejos / WENN 1 / 6

With "The Hunger Games" garnering rave reviews and grossing a historic $155 million in domestic box office, star Liam Hemsworth and girlfriend Miley Cyrus had plenty to celebrate this weekend. But did the on-and-off couple of three years cap it off with an engagement?

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On Saturday, the former "Hannah Montana" star, 19, stepped out with her Australian beau, 22, at Muhammad Ali's Celebrity Fight Night XIII event in Phoenix, Ariz.

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Cyrus wore not one but two gowns for the event, but the most eye-popping element of her look was the giant diamond ring seen on her wedding finger. The singer-actress even displayed the sparker in a Thursday tweet raving about a manicure. "I am soooo obsessed with @jennahipp nail foundations! It looks so chic and classic!" she wrote beneath the pic.

Despite a flurry of speculation over the weekend, a source close to Cyrus confirms to Us Weekly that the sparkler is not an engagement ring.

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Cyrus and Hemsworth hit it off while filming the 2009 romance "The Last Song," and despite an August 2010 split, they reconciled less than a year later.

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