Eriksson famously chose to take Theo Walcott rather than Defoe to Germany - and Defoe gained some sort of revenge at White Hart Lane.
With Spurs' top scorer Robbie Keane out for another two matches through suspension, he also offered head coach Juande Ramos an indication he is ready to step in.
The victory left City furious as they thought Spurs' opener was illegal.
• Sven reveals Ireland tackle regret
Pascal Chimbonda looked offside when he broke the deadlock on the stroke of half-time and even if it was not a punch that would have troubled City fan Ricky Hatton, the full-back did appear to use his arm.
Rolando Bianchi came off the bench to level matters in the second half but hopes of victory faded when Stephen Ireland was given a straight red card for a lunge on Young-Pyo Lee.
Defoe's winner came a minute later in the 83rd minute.
To rub salt in the wound, City knew they would have been back in the top four of the Barclays Premier League with a point.
But they were without the influence of Elano, the Brazil playmaker having failed to recover from a hamstring complaint, so their creativity came from Martin Petrov on the left wing.
Petrov's delivery from the flank went some way to explain why Dimitar Berbatov wanted his Bulgaria team-mate at White Hart Lane this summer.
However, with £8.8million striker Bianchi on the bench, Petrov only had Darius Vassell to aim for initially, giving Younes Kaboul time to settle after getting dropped for the midweek UEFA Cup clash against Anderlecht.
However, the young French defender's passing range was awful, and he was nowhere to be seen for City's equaliser.
At the other end, Darren Bent was wasteful. Berbatov's silky touches sent Bent through on goal in the ninth minute but Andreas Isaksson rushed out to save with his feet.
Javier Garrido picked up a booking for tripping Aaron Lennon, and from the resulting attack Berbatov was on the floor but managed to clip the ball through to Bent. He snatched at his shot with Jermaine Jenas waiting with an open goal in front of him.
Berbatov was full of invention, drilling a cross for Steed Malbranque to sweep a shot towards goal but Richard Dunne got himself in the way of the effort.
City showed pace on the break when Kelvin Etuhu, making his first start for the club, smashed into the side-netting, while Michael Johnson was patrolling the midfield area with authority on his return to action.
The opener came on the stroke of half-time, with Berbatov getting fouled on the touchline by a combination of Gelson Fernandes and Vedran Corluka. Jenas drilled the corner, Berbatov flicked and Chimbonda angered City with the finish off his arm - he also appeared to be standing in an offside position.
Eriksson responded by bringing on Bianchi for Etuhu just before the hour mark, with the substitute making an instant impact.
Spurs goalkeeper Paul Robinson would have been braced for a busy spell but he also had time to banter with the City fans, who dubbed him "England's number four'' after his recent troubles at international level.
He could do nothing about Bianchi's equaliser, the Italian striker rising to thump home a header from Petrov's corner.
City were putting Spurs under intense pressure and Lee had to make a last-ditch clearance from another Petrov cross. Petrov also fizzed a long-range effort just wide.
The game turned when Ireland was given his straight red card by Mark Halsey for a slide on Lee.
Defoe grabbed the winner from the free-kick, with Malbranque curling a cross off the post and the substitute smashing the rebound between Micah Richards' legs.
Sven reveals Ireland tackle regret
Manchester City boss Sven-Goran Eriksson got an immediate apology from Stephen Ireland after showing him a replay of his horror challenge that turned the game against Tottenham.
Ireland was given a straight red card by referee Mark Halsey for his lunge at
Young-Pyo Lee, with Jermain Defoe grabbing the 83rd-minute winner from the
free-kick which followed.
'When I saw it from the bench I thought it was harsh but looking at it in the
dressing room I don't think we should complain about it,' said Eriksson after
the 2-1 defeat. 'We should accept it.
'I took him in front of the laptop and when we saw it together there was
nothing to say. Of course, he apologised and is sorry.'
Ireland has been no stranger to controversy this season, with the infamous
'Grannygate' saga while on international duty and also dropping his shorts after
scoring against Sunderland.
But Eriksson is confident Ireland's unpredictable streak will not threaten his
career.
'Stephen Ireland is a young, very good football player, and he will get
better and better,' said the Swede.
'He should not have done the tackle but he did it - a week ago Robbie Keane
did something similar and was sent off. They are great footballers. Sometimes
adrenaline goes inches too high. It's not a problem, he plays a heavy price for
it.'
Ireland's tackle, though, arguable cost City the point they needed to go back
into the top four of the Barclays Premier League.
Rolando Bianchi had cancelled out Pascal Chimbonda's controversial opener.
Chimbonda appeared to be offside when he nudged in the game's first goal.
Even if it was not a punch that would have troubled City fan Ricky Hatton, the
full-back did appear to use his arm to divert Dimitar Berbatov's flick on the
stroke of half-time.
'It's nothing to discuss, the referees in this country are honest and always
try to do their best,' Eriksson said.
Bianchi was brought on just before hour mark and made an instant impact,
thudding home a header from Martin Petrov's corner.
City looked like seizing the initiative until Ireland's tackle.
Defoe came off the bench to show Eriksson what he was missing when he left him
out of England's World Cup squad last years.
'It's a little bit late if he wants to prove a point to me today - I will not
be the next man for the job,' said Eriksson.
'He is one of the better strikers but the situation, which was a long time
ago, was that he didn't play many games during the year. That was the reason why
I took one who almost never played. I gambled. That was the reason. Of course he
is a good player.'
Defoe has struggled for starts but with Robbie Keane suspended for another two
matches can expect a run in the starting XI.
'It's true that Defoe definitely helps the team when he comes on,' said
Spurs head coach Juande Ramos.
'But I have four centre forwards I have to choose between. He's one of them.
'Obviously we now only have three forwards to choose from so the minutes will
get shared around - mathematically he has more chance of playing.
'There's no one, two, three or four in order. We simply have four
centre-forwards to play in two positions, so two can play each game and two have
to sit it out.'
The win puts Spurs up to 13th in the table after a series of late goals cost
them points.
'We've lost some very important points in last minutes of games, or in
injury-time,' added Ramos.
'We hope this is a turning point which gives us an impetus to go further up
the table.'
Tottenham Hotspur 2 - 1 Manchester City
