Promotion-chasing Wolverhampton Wanderers visited London Road in search of their third consecutive victory and Ebanks-Blake put them on course with his 38th-minute penalty.
After Grant McCann had given away possession in his own half, Kevin Doyle picked up the ball and played in his strike partner, who was fouled by Gabriel Zakuani. Ebanks-Blake stepped up to convert the spot kick for his fourth of the season.
Doyle was again the provider for Wolves's second as substitute Sigurdson latched onto a through pass from the Irishman before dinking the ball over the goalkeeper and into the net.
Peterborough sit bottom of the table having lost all of their games this season, while Wolves continue to improve under Stale Solbakken.