Jakob Jantscher gave Austria a shock early lead but the game quickly turned Spain's way as Cesc Fabregas and David Villa put them 2-1 ahead by the 20th minute and the hosts had Yasin Pehlivan sent off before the half hour.
Villa struck again before the break and substitutes Dani Guiza and Pablo Hernandez, with his first international goal, added two more early in the second half.
Vincente del Bosque's team chalked up their eighth win in a row and completed their third five-goal haul in six outings, following their 5-0 win over Belgium and 5-2 demolition of Bosnia.
"The game got off to a very promising start but I think the red card interrupted the game and their (numerical) inferiority spoiled the match," said Del Bosque.
"We dominated, it's difficult to maintain concentration in this situation, but I think the team maintained the intensity."
Spain won the European championship with a 1-0 win over Germany at the Ernst Happel stadium last year.
Austria went ahead in the eighth minute when Roman Wallner squeezed between two defenders and pulled the ball back to Jantscher, who scored with a first-time shot which deflected off Sergio Ramos.
Spain replied with three goals of stunning simplicity with David Silva involved twice.
They needed only two minutes to equalise when, after Austria lost possession, Silva slipped the ball to Fabregas, who burst between two defenders and slotted the ball past Christian Gratzei.
Ten minutes later, Andres Iniesta slid a diagonal ball into the area which eluded a defender and found Villa, who turned it past Gratzei and into the net.
On the stroke of halftime, a similar pass from Silva on the right again found Villa who again managed to slip it past Gratzei.
In between, Austria midfielder Pehlivan was sent off for flattening Sergio Bustens with a clumsy late challenge.
Despite making five halftime substitutions, Spain continued the rout with Guiza taking advantage of slack defending to score in the 56th minute and Hernandez completing the rout one minute later as he turned in Jesus Navas's pass.
