Diego Simeone failed to defeat Eibar for the first time in his managerial career, but it mattered little as his side's 3-0 first leg victory ensured a ticket to the Copa del Rey semi-finals for the first time since the 2013/14 season.
Atletico Madrid's name was already half-written into the final four places, but an away goal from Jose Maria Gimenez at the very beginning of the second half dotted the i's and crossed the t's as Eibar then required five goals.
Substitutes Sergi Enrich and Pedro Leon pulled two of them back to spare their side's blushes, but a late Juanfran chip made it 2-2 on the night.
Right from the beginning it looked like it would be tough night for Eibar, as Fernando Torres came close to nodding home a sixth minute corner kick, before Angel Correa whipped a volley over the crossbar a few minutes later.
Los Colchoneros again looked dangerous when a 22nd minute Nico Gaitan free-kick bounced awkwardly towards goal, but nobody could make the finishing touch and Yoel Rodriguez was able to make the catch.
Yet Los Armeros also showed their set piece potential when Josue Dorrio almost scored his first goal for the club as he provoked a leaping save from Miguel Angel Moya with a top-corner-bound volley from an Eibar free-kick.
Overall, though, the visitors looked the most likely to score and Kevin Gameiro had a couple of sights of goal, forcing Mauro Dos Santos into an impressive sliding block, while he was also a few inches and one offside flag away from being through one-on-one.
The scoreboard remained level by the time the half-time whistle sounded, but it took just four minutes of second half action for Gimenez to head in an away goal from a Gaitan corner, squeezing out the last drop of Eibar's hope from the tie.
Now needing five, the minnows sent ball after ball into Moya's penalty area, but initially they couldn't find the back of the net.
However, the introduction of Pedro Leon and Sergi Enrich had an instant impact as the latter scored with his first touch, converting the rebound after the former had struck the post in the 73rd minute.
Leon then grabbed one of his own to send Ipurua into a frenzy, but Juanfran was able to produce a delicate chip to level the scores on the night and to put a positive spin on the trip.
- Match Sheet:

2 - Eibar: Yoel; Capa, Dos Santos, Galvez, Ruben Pena; Fran Rico (Dani Garcia, 35), Rivera; Josue (Enrich, 72), Sarriegui (Leon, 72), Bebe; Nano.

2 - Atletico Madrid: Moya; Juanfran, Gimenez, Savic, Lucas; Correa, Gabi, Saul (Koke, 62), Gaitan (Vrsaljko, 75); Gameiro (Carrasco, 62), Torres.

Goals: 0-1 (Gimenez, min 49), 1-1 (Enrich, min 73), 2-1 (Pedro Leon, min 81), 2-2 (Juanfran, min 85)

Referee: Santiago Jaime Latre

Yellow cards: Fran Rico (min 16), Lucas (min 40), Bebe (min 60)

Stadium: Ipurua

Attendance: 4,000