Mr Mayer took the record with 9,126 points on Sunday September 16, during the 42nd Décastar event in the Pierre Paul Bernard stadium in Talence (Gironde, Nouvelle-Aquitaine).
This beat Mr Eaton’s previous record of 9,045 points, which the American had achieved in the 2015 world championships in Beijing, China.
This now makes Mr Mayer the decathlon world champion, and the first Frenchman ever to hold the world record for the event.
Mr Mayer took the record after completing the two-day event at the height of his ability, including completing the 1,500m run in four minutes and 35 seconds, and succeeding his best-ever javelin throw of 71.90 metres on his third throw.
Olalalaaaaa 71m90 pour Kévin Mayer au 3ème essai du javelot !!!! Nouveau record personnel !!! Et le record du monde qui s'approche tout doucement ! #Decastar2018 et #gironde @decastar_off pic.twitter.com/qX5BbsOYzS— France Bleu Gironde (@Bleu_Gironde) September 16, 2018
Mr Eaton, the former world record holder, who has now retired from competing, congratulated Mr Mayer on his victory this weekend, writing on Twitter that his achievement was “an incredible display of ability”.
He added that it had always “been important to me to keep pushing the limit and inspiring others to do the same”.
In a later tweet, he said that despite being retired, he is still “looking to get involved [in the sport] and help improve things for athletes and the next generation”.
That was an incredible display of ability! I'm super happy for @mayer_decathlon & even more for the future of the decathlon. Important thing to me has always been to keep pushing the limit and inspiring others to do the same. The more 9k can become commonplace the better. Alle!— Ashton Eaton (@AshtonJEaton) September 16, 2018
The victory comes after a chequered year for Mr Mayer, who dropped out of the European Championships in August - despite being the favourite for a gold medal - after committing three fouls in the long jump event.
The Décastar event was founded in 1976 by French athlete Guy Drut, and was registered with the IAAF Combined Event World Challenge in 1998, cementing its place in the athletic decathlon calendar.
Decathlon is a ten-part event, including runs of 100m-1,500m, long jump, high jump, shot put, hurdles, javelin throw, pole vault, and discus.
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