[5] In what was named as a contender for LiverKick.com's "Upset of the Year",[6] she defeated Erika Kamimura by unanimous decision after an extension round was needed to separate the pair in their quarter-final match.
Kamimura had a slight edge in the striking, but Klijn used the clinch to her advantage and was able to score a shoot point in the extension round which was the difference.
[7][8] She made her return to shoot boxing in a 53.5 kg/118 lb bout at Shootboxing 2013: Act 2 on April 20, 2013, and took a majority decision win over Miyo Yoshida.
[11][12] In a -50 kg/110 lb non-tournament bout during the 2013 Shoot Boxing Girls S-Cup Japan Midsummer Festival on August 3, 2013, Klijn lost to Rena Kubota by majority decision following an extension round.
[13] Klijn lost to Iman Barlow by UD at -54 kg/119 lb Enfusion Live 15 in Dublin, Ireland on March 22, 2014.