Atletico Madrid took a significant step towards the Champions League quarter-finals with a 4-2 win at Bayer Leverkusen on Tuesday night.
Saul Niguez and Antoine Griezmann gave Atletico a 2-0 half-time lead at the BayArena.
Kevin Gameiro, with a penalty, restored the two-goal advantage after Karim Bellarabi had pulled one back.
But Stefan Savic diverted the ball into his own net to further cut Atletico's advantage, before Fernando Torres struck four minutes from time to give the visitors four away goals and a commanding first-leg lead.
The return takes place at Estadio Vicente Calderon on March 15, when the Rojiblancos will seek to advance to the last eight of the European Cup for the ninth time.
Atletico, runners-up in last season's Champions League to rivals Real Madrid, had lost on their prior three visits to Germany.
Leverkusen reached the 2002 final when the tournament had a second group stage, but had lost all four previous last-16 ties.
The clubs met two seasons ago at the same stage, with Atletico advancing following a penalty shootout, while Leverkusen have also been beaten by Liverpool, Barcelona and Paris St Germain in the last 16.
Leverkusen were runners-up to Monaco in the group stage, while Diego Simeone's side finished ahead of Bayern Munich.
And they seemed intent on showing why from the start, meeting Simeone's demand for a high intensity game.
Griezmann had an early effort saved by Bernd Leno and then Wendell sliced an attempted clearance of Felipe Luis' cross on to his own bar.
Leverkusen's escape lasted only a few more minutes as Atletico took the lead on the counter attack.
Niguez cut in from the right and, left-footed, curled the ball inside the far post from just inside the area.
A second soon followed. Aleksandar Dragovic sliced a clearance back towards his own goal.
Gameiro stole the ball and found Griezmann, who finished precisely off the bar.
Miguel Angel Moya saved from Kevin Kampl before Griezmann was denied his second and Atletico's third when Leno saved a one on one.
Leverkusen had a goal back three minutes into the second half. Benjamin Henrichs crossed from the right and Bellarabi converted into the bottom corner. It was his fourth goal in his last five Champions League games.
Leverkusen let Atletico re-establish their lead after 59 minutes when Dragovic hauled back Gameiro, who converted the penalty himself.
Nine minutes later and it was 3-2 as Julian Brandt's low cross caused trouble for the Atletico defence. With Javier Hernandez poised to pounce, Moya pushed the ball against Savic and it ricocheted in.
That was not all, though, as Atletico had the final say.
Substitute Torres met a right-wing cross from Sime Vrsaljko with a glancing header into the bottom left corner.
It was the former Liverpool and Chelsea striker's fourth goal in five games for Atletico, having failed to score in his previous 17. And it was a vital one.