The Chelsea striker struck twice in each half and missed a second-half penalty while Barcelona forward David Villa also netted a hat-trick here on Thursday.
Tahiti are now out of contention for the semi-finals with one group match still to play in the World Cup warmup tournament.
Torres opened the scoring in the fifth minute after running onto a Juan Mata pass and sliding an angled shot that beat goalkeeper Mikael Roche at the near post.
Buoyed by the partisan support of a near-capacity crowd at the Maracana stadium Tahiti did not let the early goal dampen their mood.
The Pacific islanders repeatedly threatened La Roja on the counterattack and had a penalty claim waved away when Steevy Chong Hue went to ground under a Cesar Azpilicueta tackle.
But Spain soon found their composure, quelling Tahiti's early spirit with their trademark tiki-taka passing game.
David Silva doubled the world champions' lead with a cool finish after Villa's pass before Torres rounded goalkeeper Mikael Roche to make it 3-0.
Silva then returned Villa's favor by threading a perfectly weighted pass to the former Valencia forward, whose low shot left Roche with no chance.
The half-time break did little to stem the momentum of Vicente del Bosque's side. Villa poked in his second after Nacho Monreal's cross and Torres clinched his hat-trick with a first-time finish following substitute Jesus Navas' pull-back from the right.
Roche gifted Villa his third by failing to grasp a tame Javi Martinez shot in the 64th minute.
With crowd willing them on, the reigning Oceania champions were again sparked into action.
They produced their best two chances of the match within a minute when ChongHue and Jonathan Tehau forced consecutive saves from La Roja goalkeeper Pepe Rene.
But Spain were true to their pre-game vow not to show mercy on their opponents.
Juan Mata slotted in the team's ninth in the 67th minute before Torres prompted celebrations from Roche, and the crowd, by sending his 77th-minute spot-kick crashing against the crossbar.
The 29-year-old made amends a minute later by wrong-footing the keeper for the second-time in the match and rolling in his fourth goal.
Silva then scored his second on the stroke of full-time with a clever turn and low shot past Roche.
After the match Tahiti formed a guard of honour as Spain entered the players' tunnel, a gesture that drew warm applause from the crowd.
Eddy Etaeta's side were then given a raucous ovation, and they remained on the pitch for several minutes to show their appreciation.
Tahiti will play their final group match against Uruguay in Recife Sunday while Spain faces Nigeria in Fortaleza the same day.