Panathinaikos gave themselves an excellent chance of qualifying for the Champions League quarter-finals by scoring a vital away goal in the first leg of their last-16 clash with Villarreal.
Giorgos Karagounis gave the Greek side the lead midway through the second half in Spain and although Guiseppe Rossi equalized with a penalty seven minutes later, Henk Ten Cate's men will fancy their chances of going through when the teams meet in Athens in a fortnight.
Playing in the knockout rounds for the first time in seven years following three consecutive wins in the group stage, Panathinaikos had few chances but stifled Villarreal, who squandered a number of opportunities, particularly in the first half.
The hosts were the first to threaten when Angel Lopez latched on to Marcos Senna's raking cross-field ball, cut inside and shot from the right corner of the box but Mario Galinovic was equal to it, saving well with his legs.
The visitors made their first real foray forward in the 10th minute but Evangelos Mantzios was just caught offside chasing a clever ball from Gilberto Silva.
Mantzios then blasted over the crossbar from a corner and at the other end Rossi fired a free-kick straight at Galinovic.
As Villarreal began to dominate, a neat exchange between Senna and Rossi created an opportunity for the latter in the 20th minute but Giannis Goumas made a superb last-ditch tackle to deny the striker the chance to shoot.
Karagounis made his first contribution midway through the half when his 20-yard strike was comfortably held by Diego Lopez, but Villarreal quickly responded with another chance for Rossi, who was again thwarted by Galinovic.
The hosts could have gone behind just after the half-hour mark when Diego Lopez, in catching a Karagounis free-kick, stepped back over his goal line but although television replays suggested the ball may have gone over, the referee waved play on.
Villarreal continued to have the upper hand after half-time but could not break the deadlock, Rossi mistiming a header which looped straight to Galinovic.
That chance summed up the lack of quality on show at El Madrigal and neither team produced anything to suggest they will go beyond the next round.
Panathinaikos injected a much-needed spark into the match in the 59th minute when Karagounis burst through from a counter-attack and unleashed a rasping right-footed shot into the top left corner.
Galvanised by the goal, the visitors almost doubled the lead when Mantzios flummoxed the Villarreal defence with some neat skill and a fierce shot but Diego Lopez turned away his effort.
The Yellow Submarine were soon level though, the instrumental Rossi firing home from the spot in the 66th minute after he was fouled by Jakub Wawrzyniak.
Substitute Robert Pires provided some flair as Villarreal pressed for a winner but he, Rossi and Senna were all denied in the closing stages.
