Panathinaikos quickly asserted themselves against the Welsh minnows and were duly rewarded for their dominant start as they forged a 15th-minute lead.
Goalkeeper Connor Roberts has emerged as a talismanic-like figure during the Saints’ debut European campaign, but he was left helpless to prevent Filip Đuričić’s close-range finish.
Roberts had denied the Serbian marksman just moments earlier with a fine one-handed save, but when Đuričić latched onto Giorgos Vagiannidis’s low cross, a second reactive save from Roberts saw the ball fall kindly back into the path of the Panathinaikos striker, who comfortably finished.
Willian Arão’s header flashed dangerously over Roberts’ crossbar, but for all their dominance, Panathinaikos were unable to extend their advantage. That allowed the Saints to muster the confidence to occasionally craft their own attacking advances as the Greek side took their slender lead into the break.
The Saints’ hopes looked to rest largely on Ryan Brobbel, who schemed in pockets of space out wide but the visitors continued to remain on the front foot. Panathinaikos had led first in three of their four games to date, but they had only won once.
Yet when Danny Davies was caught in possession inside his own area and conceded a penalty, TNS’s evening unravelled as Fotis Ioannidis confidently dispatched into the bottom-left corner to double the visitors’ lead.
Bartłomiej Drągowski held onto a well-struck free-kick from Declan McМanus to thwart any hope of the Welsh champions staging a late comeback, securing Panathinaikos a rare European win on away soil. The victory provides a lift for the 20-time Greek champions, who conclude their league phase schedule against Dinamo Minsk.
Meanwhile, the defeat leaves TNS on the verge of exit from the competition and requiring a result from their final game in Slovenia against NK Celje.
Flashscore Man of the Match: Anastasios Bakasetas (Panathinaikos)