Aberdeen were given a tough lesson in European football as they lost their first Uefa Cup Group B match to Panathinaikos in Athens.
Panathinaikos players celebrate Goumas' goal against Aberdeen
Austrian midfielder Andreas Ivanschitz helped create all three goals after Chris Clark had seen an early Aberdeen shot clear the crossbar by inches.
Giannis Goumas headed the first for Panathinaikos on 10 minutes.
Dimitrios Papadopoulos provided the killer blow late on before Dimitris Salpigidis completed a comfortable win.
The result also means that a Scottish club has yet to win on Greek soil.
Clark, Scott Severin, Michael Hart and Andrew Considine overcame knocks to take their places in the Aberdeen team.
Darren Mackie missed out through injury, so Lee Miller started as the solitary striker in a 4-5-1 formation.
Panathinaikos coach Jose Peseiro rewarded weekend goalscorers Salpigidis and Ivanschitz with starting berths.
The Greeks forced a number of corners in the opening minutes, but it was Aberdeen who were first to threaten after five minutes.
Lee Miller and Barry Nicholson combined well to release Derek Young down the right.
Young raced to the byeline and picked out Clark who shot inches over from 12 yards.
However, it was the Greek side who took the lead following Ivanschitz's whipped-in free-kick from the right.
Captain Goumas met the ball with a glancing header across goal and into the far corner past Langfield.
Mikael Nilsson tussles with Aberdeen's Richard Foster
The goal seemed to rock the Dons momentarily, as just six minutes later Langfield was called upon again.
Invanschitz tore into the box and cut the ball back for Senegalese striker Dame Ndoye, but Langfield pulled off an excellent save.
Aberdeen captain Severin was harshly cautioned when he won the ball cleanly in midfield from Ndoye, who was stretchered off in great distress.
But Ndoye recovered to win a free-kick after going past Considine, before appealing for his opponent to get booked.
Aberdeen regained their composure to finish the half well and Severin's shot from 25 yards was just too high.
Within a minute of the re-start, Zander Diamond did well to force Ndoye to shoot wide.
However, the Senegalese continued to frustrate by going to ground easily when challenged.
Nicholson was foiled after 55 minutes, when the ball was taken off his head as he dived to meet it six yards out.
The home side had a penalty claim waved aside when Salpigidis crumpled under Michael Hart's challenge.
But, with less than 20 minutes left, substitute Papadopoulos made the points safe for Panathinaikos after receiving a defence-splitting pass from Ivanschitz.
And, with the Greeks in full flow, Salpigidis made it three from close range after 77 minutes, when Langfield could only parry Ivanschitz's free-kick into the striker's path.
Panathinaikos: Malarz, Morris, Fyssas, Goumas, Mattos, Tziolis, Ivanschitz (Seric 81), Nilsson, Dimoutsos, Ndoye (Papadopoulos 59), Salpigidis (Mantzios 81).
Subs Not Used: Galinovic, Sarriegi, Romero, Vyntra.
Goals: Goumas 10, Papadopoulos 73, Salpigidis 77.
Aberdeen: Langfield, Hart, McNamara (De Visscher 75), Diamond, Foster, Considine (Mair 61), Severin (Aluko 86), Nicholson, Clark, Miller, Young.
Subs Not Used: Kelly, Byrne, Lovell, Touzani.
Ref: Thomas Einwaller (Austria).