* Martin joins Cancellara with fourth title * Defending champion Kiryienka takes silver * Dumoulin disappoints with 11th-place finish (Adds details, quotes) Oct 12 (Reuters) - German Tony Martin claimed a record-equalling fourth individual time trial world title when he crushed his rivals to prevail on the 40-km flat course in Doha on Wednesday. Martin, who was instrumental in Etixx-Quick Step's team time trial title last Sunday, clocked 44 minutes 42.99 to beat defending champion Vasil Kiryienka, of Belarus, by 45.05 seconds. Spain's Jonathan Castroviejo finished third, 1:10.91 off the pace in searing heat as temperatures rose above 40 Celsius. More...