Captaining a second-string Atletico side playing just four days on from their Europa League final success against Marseille in Lyon, Torres soon cancelled out Kike Garcia's 35th-minute opener just before the break.
He rolled back the years with a fantastic run and delicate finish to score on the hour but teammate Lucas Hernandez was sent off three minutes later and Atletico had to battle on with 10 men.
Eibar quickly made their numerical advantage count, with Ruben Pena hammering in a long-range strike to equalise with 20 minutes remaining.
Torres was denied a dream ending when an offside flag saw another effort ruled out and the striker finished his career for his boyhood club with 128 goals in 404 matches over two spells.
Earlier on Sunday, goals from Simone Zaza and Goncalo Guedes gave Valencia a 2-1 win over already relegated Deportivo La Coruna.
Zaza finished a slick Valencia passing move at the far post after 28 minutes to register his 13th goal of the season, before seeing an effort strike the crossbar early in the second half.
In the 77th minute Guedes drilled a low shot into the bottom corner for the second goal and Lucas Perez hit a consolation for Depor with 10 minutes remaining but fourth-placed Valencia held on for the three points.
Espanyol's strong finish to the campaign continued with a final-day victory at Athletic Bilbao. David Lopez struck the only goal of the game after nine minutes as the Barcelona club concluded with a fourth win in a five-match unbeaten run.
In the late kick off, Andres Iniesta's final Barcelona appearance ended in victory on an emotional evening at the Nou Camp.
LaLiga champions Barca, who lost their unbeaten record in a 5-4 loss at Levante last week, responded with a 28th win of the season, defeating Real Sociedad 1-0.
Former Liverpool forward Philippe Coutinho, scorer of a hat-trick a week ago, netted the only goal on a night which belonged to Iniesta.
The Spain playmaker was substituted after 81 minutes and received a rapturous reception as he bade farewell to the stage he has graced for so long and so successfully.
The 34-year-old will leave the club this summer 22 years after joining their academy, having won 32 major honours including four Champions League titles and nine LaLiga titles.
He took his time to depart, embracing team-mates and soaking in the adoration.
With tears in his eyes, the man who was given a contract for life just last October, concluded his illustrious spell as a Barca player.
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