The 28-year-old opened the scoring for the visitors after 10 minutes but received his marching orders after a high challenge on Santi Cazorla which left referee Howard Webb with no option but to brandish a straight red.
And, while the Spurs forward stresses that his tackle was in no way malicious, he accepts that his actions cost his side the victory - which leaves them 11 points off league leaders Manchester City.
"I completely understand my sending-off changed the entire outcome of the game and I wholeheartedly apologise to my team-mates, the manager and all the Tottenham fans for letting them down," he told The Sun.
|10/1||Emmanuel Adebayor is 10/1 with William Hill to score two or more goals against Lazio
"I so much wanted to help Tottenham win and thought for a moment that I'd actually set that win up when I scored but football changes so quickly.
"One minute a hero, the next a villain."
However, the forward suggested that, while his tackle was foolish so early on in the game, it was an honest attempt to regain possession, with Cazorla being too quick for him.
"I must stress that my challenge was not malicious in any way whatsoever," Adebayor continued.
"I was genuinely trying to win the ball and probably stretched my foot out a bit too far in the heat of the moment."