Costel Pantilimon was forced into just two serious saves before the interval on his return to the club he left last summer after only seven Premier League starts in three years.
Vlaar was the game's outstanding performer and Guzan did not have to make a serious save in the Villa goal.
Blackburn striker Roque Santa Cruz forced Mark Schwarzer into his only serious save before half-time while Brett Emerton curled a shot against the post.
Edwin van der Sar did not have a serious save to make, though in injury-time the £9.5m debutant Albert Luque nearly made Van der Sar work with a neat trick and shot.
Cahill scored his second and Australia's fourth goal after 64 minutes with a typically excellent header from a cross by Luke Wilkshire on an afternoon when the Australian goalkeeper, Mark Schwarzer, only had to make one serious save, thwarting striker Sunil Chhetri six minutes from time.
It was not until the 80th minute that Lukasz Fabianski had a serious save to make, when the Swansea goalkeeper tipped Papy Djilobodji's header on to the bar, and by then the game was well beyond Sunderland, who are now bottom again after three wins in four had improved their standing.
