Ronda Rousey submitted Sarah Kaufman in 54 seconds of the...

Ronda Rousey submitted Sarah Kaufman in 54 seconds of the first round to defend her Strikeforce women's bantamweight title. (Aug. 18, 2012) Credit: Showtime/Esther Lin

Don't blink or turn your head or send a text message after you click play on the embedded video above. You just might miss Ronda Rousey beating Sarah Kaufman.

Rousey made the first defense of her Strikeforce women's bantanweight championship a quick one as she submitted Kaufman in 54 seconds via armbar. That makes it six pro MMA fights and six pro armbar submissions for Rousey.

And here's Rousey in her backstage interview after the fight.

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