Liverpool manager Juergen Klopp enjoyed a satisfying return to Borussia Dortmund as his new side frustrated his former charges and claimed a valuable away goal to draw 1-1 in their Europa League quarter-final, first leg on Thursday.
Klopp, whose seven-year Dortmund spell ended last season, was warmly welcomed back to the Westfalenstadion and enjoyed his night as Liverpool took a first-half lead through Divock Origi before Mats Hummels levelled after the break.
Holders Sevilla are well-versed in the art of getting results in two-legged knockout ties and their bid for a third successive Europa League title stayed firmly on course with a 2-1 win at La Liga rivals Athletic Bilbao.
Villarreal, the third Spanish club in the last eight of Europe's second-tier competition, also enjoyed first-leg success with a 2-1 win at home to Sparta Prague, while Shakhtar Donetsk won at Braga by the same scoreline.
Klopp's return was always going to be an emotionally-charged occasion for the Liverpool boss and the Dortmund fans, whose affection for their former coach, who delivered two Bundesliga titles, remains undimmed since his departure.
There was warm applause from all around the stadium as Klopp was welcomed back prior to kickoff and the spirit of friendship between the teams extended to a unified and rousing rendition of both clubs' anthem "You'll Never Walk Alone".
Dortmund have been in superb form -- unbeaten in 16 matches in 2016 -- but they were sluggish in the opening 45 minutes when Liverpool chased, harried and pressed relentlessly.
The visitors took the lead after 36 minutes when industrious Origi, preferred in attack to Daniel Sturridge, latched on to a flick forward, took a touch to control the ball and squeezed a low shot across Roman Weidenfeller into the net.
The Belgian should have doubled the lead before halftime but shot straight at Weidenfeller and Liverpool were made to pay three minutes after the break when Hummels powered a header from Henrikh Mkhitaryan's cross past Simon Mignolet.
Liverpool comfortably survived Dortmund's best efforts for the remainder of the match and will head to Anfield buoyed by their performance, with a knee injury for captain Jordan Henderson the only disappointment for Klopp.
"Dortmund is a pretty good side and everyone could see that but we had our moments and we could have won the game," Klopp told BT Sport.
"I’m pretty sure a lot of people thought we would lose 2, 3 or 4-0. But at some moments we had Dortmund and around our goal we were brilliant."
Sevilla, aiming to become the first side to lift the trophy for three years running, but had not won an away game in Europe or La Liga all season and were behind early in the second half.
Atheltic's Aritz Aduriz, the Europa League's top scorer this season, got his ninth in the competition when he dipped low at the back post to head Iker Muniain’s cross past keeper David Soria three minutes into the second half.
The two teams, locked together on points in La Liga, were level on the night, however, when Muniain's poor header back was intercepted by Ever Banega, who fed Timothee Kolodziejczak to finish left-footed after 56 minutes.
The comeback was complete with seven minutes remaining when Kevin Gameiro found Vicente Iborra on the counter and he poked the ball past Bilbao keeper Iago Herrerin.
Shakhtar Donetsk started their game with Braga on the back of an 8-1 domestic victory over Metalist Kharkiv, in sharp contrast to their Portuguese opponents, who lost 5-1 to Benfica in their last outing.
The Ukrainian side took the lead through Yaroslav Rakitskiy's volley just before halftime, and Facundo Ferreyra doubled the advantage with 15 minutes remaining when he diverted a cross into the Braga net.
Wilson Eduardo gave Braga a lifeline, however, when he headed home in the 89th minute.
Villarreal came into their clash against Sparta Prague with a 100 percent record at home in Europe this season without having conceded a goal, while Sparta had gone 12 matches unbeaten in the competition.
Something had to give and Villarreal will head into the second leg as favourites after Cedric Bakambu's scored either side of Jakub Brabec's equaliser to give them the advantage heading into next Thursday's return fixtures.