Kayla Harrison

United States' Kayla Harrison celebrates her gold medal after defeating France's Audrey Tcheumeo in the women's 78-kg judo gold medal match at the 2016 Summer Olympics in Rio de Janeiro, Brazil, Thursday, Aug. 11, 2016. (AP Photo/Jae C. Hong)

RIO DE JANEIRO (AP) -- American Kayla Harrison has successfully defended her Olympic judo title in the women's 78-kilogram division, after beating France's Audrey Tcheumeo in a tense final Thursday at the 2016 Rio Olympics.

With just six seconds left, Harrison caught Tcheumeo's arm in an armlock, and forced Tcheumeo to tap out in submission, automatically winning the contest.

Harrison's coach, Jimmy Pedro, said Harrison's achievement was enormous, given that there have been no repeat Olympic judo champions at Rio or at the previous games in London.

Harrison, from Middletown, Ohio, was in commanding form throughout Thursday, winning her preliminary matches automatically after pinning her opponents down to the mat for 20 seconds; her first match lasted just 43 seconds.

Pedro said Harrison was "on fire" on Thursday and described her defense of her Olympic title as "epic."

The women's bronze medals were won by Brazil's Mayra Aguiar and Slovenian Anamari Velensek.

BACK. TO. BACK. 🏅🏅@Judo_Kayla has made HISTORY as the first U.S. judoka to win back-to-back #GOLD! pic.twitter.com/tGAt4e9Mxc — Team USA (@TeamUSA) August 11, 2016

That feeling when you win your SECOND #GOLD!



CONGRATS @Judo_Kayla - #TeamUSA is SO PROUD of you! pic.twitter.com/Yq3GsCvS3N — Team USA (@TeamUSA) August 11, 2016