A tentative start from both sides saw little in the way of goalmouth action, with Cucho Hernández’s header, which was brilliantly saved by Alban Lafont, the closest either team came to opening the scoring in the early stages.
Betis soon took control and forced several corners, and it would be 15 minutes before Panathinaikos had a sight of goal, but Georgios Kyriakopoulos screwed his effort horribly wide.
As the half progressed, the visitors continued to dictate the tempo and pattern of the game, holding over 70% possession to leave their Greek hosts chasing shadows for long periods.
Lafont had to get down swiftly to keep Hernández’s low shot out just after the 30-minute mark, but despite having the lion’s share of the ball right up until half time and stopping Panathinaikos getting a shot on target, Betis were unable to make their dominance count.
Facundo Pellistri was a little more lively at the beginning of the second half, and Andrews Tetteh had a reasonable shout for a penalty turned down as the hosts looked to take the game to their LaLiga opponents.
That sparked Betis back into life, and Hernández was a whisker away from opening the scoring.
As the hour mark approached, Anass Zaroury was handed his second yellow card in 10 minutes when he hauled back Abde Ezzalzouli, reducing Panathinaikos to 10 men for the final half-hour.
To their credit, Rafa Benítez’s side continued to try and take the game to Betis, but with 15’ to play, they still hadn’t managed a shot on target despite their industry.
By contrast, Antony’s long-range effort, which brought the best out of Lafont, was the visitors’ fifth.
However, just a minute after coming on, Karol Świderski was hauled over by Diego Llorente, and after a VAR review, a penalty was awarded and the Spaniard sent off.
Taborda stepped up to fire home the winner with the hosts' first effort on target, and the result means that the Greek giants preserve their great recent home record, which has seen them lose just one of their last 13 matches at Apostolos Nikolaidis Stadium (W7, D5), keeping six clean sheets in that time.
Flashscore Man of the Match: Cucho Hernández (Real Betis)