Spain international Fernando Llorente struck twice as Athletic Bilbao progressed to the knockout stages of the Europa League with a convincing 3-0 victory over Austria Vienna in a match marred by crowd disturbances.
Llorente, who started the game as the joint-leading scorer in the competition with five other players on four goals, put Athletic ahead in the 20th minute before Mikel San Jose smashed home the Basque side's second on the hour.
Soon after that goal the match was suspended for around 25 minutes following ugly disturbances in the stands at the Franz Horr Stadion.
Play was initially stopped after objects were thrown onto the pitch, and then the Athletic players raced to the changing rooms as supporters climbed over a fence and invaded the playing surface.
Riot police formed a line just outside the penalty area while the Austria team spoke with the supporters to try to calm the situation.
Eventually the match was able to restart after a delay of almost half an hour, and in the remaining time Athletic created further chances before Llorente netted his second of the game to seal an impressive win.
The victory means Athletic join Group L leaders Werder Bremen in going through to the last 32, and the two teams will face each other for top spot at San Mames in the final round of matches.
It took in-form Athletic just 19 minutes to go ahead with Llorente scoring after the visitors had hit the crossbar twice in quick succession.
Fran Yeste was first to strike the woodwork when Austria goalkeeper Szabolcs Safar tipped his free-kick onto the bar, and then when Javi Martinez retrieved the loose ball and crossed it back into the box, San Jose saw his powerful header crash back off the frame of the goal.
Athletic were not to be denied though, as San Jose's header fell to kindly for Llorente, who scuffed the ball past Safar to put the Primera Division side ahead.
Austria, knowing nothing other than a victory would do if they were to continue in the competition, tried to recover and Zlatko Junuzovic brought a diving save out of Gorka Iraizoz before Milenko Acimovic curled a free-kick just inches wide of the top corner.
The match was delayed just after half-time due to a lack of visibility caused by flares, but unlike the later incident, play was able to resume fairly promptly and Athletic took advantage to double their lead through San Jose.
The defender provided a classy finish to an ugly goalmouth scramble as he smashed an unstoppable volley off both the underside of the crossbar and the far post to make it 2-0.
That was virtually the last action before the unrest in the stands started and forced the match to be delayed.
When the teams returned later on, Yeste and Llorente both missed decent openings to make it 3-0 before the latter managed to do just that with five minutes to go when he slotted home Joseba Etxeberria's cross at the far post following a defensive mistake.