Dosáhnout and dosiahnuť

I found out yesterday that Slovak, the most closely related language to Czech, makes use of a different case after the verb dosiahnuť, to achieve, to reach. Czech dosáhnout requires the genitive (Víme, jak dosáhnout předních míst ve vyhledávačích), whereas Slovak dosiahnuť requires the accusative (Vieme, ako dosiahnuť predné miesta vo vyhľadávačoch). Maybe that is why I remember seeing dosáhnout with the accusative in a Czech text. It is probably a Slovakism.