In a game of few chances, Chopra coolly slotted home when Ross Wallace's cross fell to his feet, picking his spot in the corner from eight yards.
We'd had a warning minutes earlier when Paul Robinson made the save of the game from Dickson Etuhu and when the winner arrived, it proved a killer blow - we barely had time to restart.
Until those last few minutes, a high-intensity opener almost bereft of goalmouth action had a goalless draw written all over it.
Martin Jol's opening gambit for the campaign was a full Premier League debut for Younes Kaboul alongside Anthony Gardner in the heart of defence, with Michael Dawson absent after turning an ankle in training on Friday. Paul Stalteri was the nominated left-back, playing behind Steed Malbranque.
Teemu Tainio was assigned to attack the right flank, with Didier Zokora and Jermaine Jenas patrolling the central areas. Dimitar Berbatov and Robbie Keane were the chosen starting attackers.
Red and white stripes were visible virtually all round the arena as Sunderland fans welcomed Premier League football back to their stadium after a one-year absence, while the Spurs thousands, as always, provided a vocal contrast in colours. The scoreboard did get a little confused however when our team was being read out and starting listing the Juventus line-up with Buffon in goal...
The opening exchanges did not bring anything in the way of goal threat, home striker Anthony Stokes looked a composed performer who could present problems, while to counter that Kaboul was a commanding figure at the back with a take no prisoners approach.
Jenas was teed up for the first shooting opportunity of the game just before the 11 minute mark after good work from Malbranque down the left, but his shot was some way wide of troubling £9m goalkeeper Craig Gordon. A teasing cross from Malbranque did create a degree of doubt in the mind of the Scot four minutes later, with the ball just evading the on-rushing Keane at the far post.
A Jenas chip into the path of Berbatov was prevented from development by the flag of the assistant referee before a raking Tainio switch that picked out the chest of Berbatov led to Keane dispatching a shot that Gordon was able to field with comfort.
Some neat passages of progressive passing followed, but the attacking third was particularly congested and the football was unable to flow.
The was a big scare at our end when Gardner misjudged a crossfield ball and Daryl Murphy was given a route through on goal. It took a great block from Paul Robinson to stop him in his tracks and Carlos Edwards couldn't pick out a teammate with the subsequent cross.
The game was sprang into life, Berbatov had a penalty appeal turned down by referee Mr Wiley five minutes before the break after rounding Gordon and seemingly being tripped by Dean Whitehead, only for Sunderland to speed up the other end and Nosworthy pinged in a shot that just cleared Robinson's right hand post.
The second half began in much the same way as the first - the contest became cagey again. Keane headed across goal from a Pascal Chimbonda cross, while a Berbatov free-kick was flighted just over from the edge of the area following a foul on the full-back.
It was time for the introduction of Darren Bent, with Tainio making way in the 59th minute. Malbranque came to the right side and Keane switched to the left in order to accommodate the change.
The giant Kaboul was displaying his own forward thinking instincts and came pretty close to working himself into a one-on-one with Gordon nearly 20 minutes into the half - he will be viewed as a big plus to emerge from this seasonal opener.
Further change came in the 77th minute with Jermain Defoe being added to the mix for Berbatov. It signalled a livening up of the game again, a little spark being ignited in the team in all white.
Tom Huddlestone was our last substitute for Didier Zokora and rifled in a volley with two minutes left but Sunderland found extra imputus as three minutes added time went up. Robinson did superbly to claw out from Etuhu and when the next chance arrived, Chopra made no mistake.
Sunderland: Gordon, Etuhu, Nosworthy, McShane, Edwards, Whitehead, Stokes (Chopra, 72), Richardson (Collins, 72), Murphy, Yorke (Miller, 58), Wallace. Subs: Ward, Connolly.
Spurs: Robinson, Chimbonda, Stalteri, Kaboul, Gardner, Tainio (Bent, 59), Jenas, Zokora (Huddlestone, 87), Malbranque, Keane, Berbatov (Defoe, 77). Subs: Cerny, Rocha.
Michael Chopra's injury time winner meant it was disappointment on the opening day at the Stadium of Light.