Rubuta ci gaba ga wannan sakin layi - Klaasen ya kai zagaye na biyu na gasar zakarun duniya ta 2012
tare da nasara 3-1 a kan Peter Wright, amma James Wade ya doke shi 0-4 a zagaye na biyu. Sakamakonsa mafi kyau na 2012 shi ne ya kai wasan kusa da na karshe na gasar UK Open na uku a watan Maris inda ya rasa 4<unk>6 ga Mark Jones. A UK Open kanta an doke shi a wasan karshe na 64 da Raymond van Barneveld 3<unk>9. Bayan bayanan da suka bayyana game da rayuwar sirri na Klaasen wanda aka bayyana a ƙasa bai sake yin wasa ba a cikin sauran 2012, wanda ya haɗa da rasa Gasar Cin Kofin Duniya ta 2013.