A week on from conceding twice to Andrews Tetteh, it took just nine minutes for Viktoria Plzen to come unstuck against the striker once again, as he combined well with Vicente Taborda before guiding the ball low into the bottom corner.
The home side gradually recovered from the early setback and carved out their first decent chance 21 minutes in with an intricate move, resulting in Lukas Cerv nodding down for Salim Lawal to fire just over. Viktoria continued to increase their share of the efforts as the half wore on, but neither Tomas Ladra, Amar Memic, nor Cerv caused any problems for Alban Lafont in the Panathinaikos goal.
At the other end, Tetteh was intent on settling the tie just before the break when he got in behind the defence and went down under a challenge from Vaclav Jemelka, only for his penalty appeal to be waved away.
The Czech side continued to pepper the Panathinaikos goal with half-chances after the break, but failed to make inroads until just after the hour mark, when Ladra tried his luck from range and forced Lafont to tip the strike around the post.
With the resulting corner, Patrik Hrosovsky delivered a precise ball to the back post, where Karel Spacil climbed highest to head home the equaliser.
Tetteh teed up Renato Sanches to hit one narrowly wide before Ladra sent a dipping effort shy of the target as the match headed for its final quarter, but those would be the final clear opportunities in 90 minutes for either side, as extra time looked inevitable.
Rafael Benitez’s side continued to turn to Tetteh for attacking inspiration in the extra 30 minutes, but his early header was wayward.
Shortly before the break, things took a turn for the worse for The Shamrock when Javi Hernandez was guilty of pushing over Prince Abu, and the Panathinaikos substitute was shown a straight red card.
Yet, not only did Martin Hysky’s team fail to use their man advantage, they needed an outstanding Sampson Dweh block to deny a glorious chance for Facundo Pellistri, and when Filip Djuricic sent a late header straight at Florian Wiegele, the match headed for penalties.
Lafont gave the Greek side the advantage immediately by saving from Memic, only for Davide Calabria to waste it, as Wiegele kept out his tame effort.
The next four penalties were scored before Cheick Souare blasted his over the top. Karol Swiderski and Matej Valenta found the net, but so did Milos Pantovic with the final effort, sending Panathinaikos through.
The 1971 European Cup finalists are now one round away from matching their best-ever UEL performances, while Viktoria exit the competition without a defeat in 90 or 120 minutes.
Flashscore Man of the Match: Andrews Tetteh (Panathinaikos)
