Pierre-Emerick Aubameyang levelled the tie in just the fourth minute, but they had to wait until the second half before really putting the tie to bed.
Christian Pulisic gave them the lead early in the second half, with Aubameyang scoring twice more to complete a hat-trick, as Dortmund reached the quarter-finals for the first time since 2014.
Benfica with the advantage
Three weeks ago Benfica won the first leg by a single Konstantinos Mitroglou goal. Dortmund, and especially main marksman Aubameyang, missed a hatful of chances, whilst Ederson also saved an Aubameyang penalty.
Dormtund have won three games straight since, with two 3-0 wins and a 6-2 thrashing of Bayer Leverkusen on Saturday. They made two changes, with Pulisic and Marcel Schmelzer in for the injured Marco Reus and Raphaël Guerreiro. Guerreiro was on the bench having been a doubt with a muscle injury.
Benfica’s 1-0 win over CD Feirense on Saturday was their seventh in a row. They made two changes, with Nelson Semedo and Franco Cervi coming in to the starting line-up. André Carrillo and Andrija Zivkovic made way.
Dortmund strike early but get bogged down
Dortmund needed just the one goal to bring the tie level and it took them less than four minutes to get it. Ousmane Dembélé’s corner was headed on by Pulisic into Aubameyang at the far post, who quickly made amends for his misses in the first leg.
Their tails were up, but they couldn’t capitalise. Marc Bartra headed over another Dembélé corner, with the young French winger then shooting wide on the counter from a Benfica corner. The away side thought that Lukasz Piszczek had handled that corner, and it did indeed hit his arm but it clearly wasn’t deliberate.
With Dortmund failing to assert their dominance, Benfica were able to grow into the game. Cervi had a relatively weak shot saved by Roman Bürki, but Luisão came closer with a header from Pizzi’s free-kick. It was over his head, but again the Dortmund goalkeeper kept it out.
Dortmund were growing frustrated, and this was symbolised by Dembélé. Having been central to most of Dortmund’s attacking play earlier in the half, he was then booked for showing dissent at one of referee Martin Atkinson’s decisions. He could have then seen a second for a careless foul on Eliseu, but the English referee showed leniency.
Pulisic and Aubameyang finish the job
Benfica had the first chance of the second half. Piszczek made a poor attempt at clearing a Semedo cross, it went straight to Cervi however the Pole redeemed himself with an excellent block.
Dortmund soon started to turn it on again though. Ederson made two excellent saves from Aubameyang, albeit the striker was offside both times.
He then made a third save from an Aubameyang shot, but Dortmund retained possession. Eventually Piszczek played through Pulisic, who chipped over Ederson to give Dortmund the overall lead for the first time.
Then in the blink of an eye they scored a third. Julian Weigl cut across the Benfica defence with a superb diagonal ball to Schmezler. He crossed it in, and Aubameyang pounced with typical precision to add daylight to the score.
That was enough to kill the tie off with Benfica shattered by the goals. Dortmund came strong again in the latter stages though, with Bartra hitting the post with a header. They then scored a fourth, with Gonzalo Castro and Eric Durm combining. Durm crossed in and set up Aubameyang’s hat-trick, completed with an easy tap-in.