Chelsea secure win over Aston Villa
Ivanovic headed in a Frank Lampard free-kick unopposed after 73 minutes, as debate raged over whether the Chelsea right-back should even have still been on the pitch.
Referee Kevin Friend had booked the Serbian defender moments earlier for catching Christian Benteke with a flailing arm in an aerial challenge which infuriated Villa boss Paul Lambert.
All the attention was on Jose Mourinho's return in Sunday's defeat of Hull, but the self-proclaimed Special One wanted to shift the focus to his team, who endured an altogether more difficult test than on Villa's most recent visit to Stamford Bridge.
Villa were beaten 8-0 last December, but were in buoyant mood following the 3-1 opening day win at Arsenal and determined to claim the scalp of another title contender.
Antonio Luna scored late on at the Emirates Stadium and was on target again, only this time into his own net following a Brad Guzan save from an Eden Hazard shot.
Benteke, whose double accounted for Arsenal, scored his third goal of the season with the final kick of the first half to equalise.
It came after a dart down the left from Gabriel Agbonlahor which is the kind of play which could bring the forward into England contention again.
Then, just as Villa looked their most threatening, Ivanovic struck Benteke before breaching the visitors' defence as Mourinho's unbeaten home record in the Premier League was extended.
The Portuguese has never lost in 62 top-flight matches at Stamford Bridge and next Monday takes his side to Manchester United for an early title bout, where transfer target Wayne Rooney is sure to be the focus of attention.
In a match rescheduled from August 31 due to Chelsea's involvement in the UEFA Super Cup against Bayern Munich a day earlier, Juan Mata and Demba Ba started in place of Kevin de Bruyne and Fernando Torres, respectively, with the latter not even on the bench.
Villa, whose manager Lambert was unhappy the date was moved to the first Wednesday of the season, named 10 of the players who started at Arsenal, the one enforced change as Ciaran Clark started in place of the injured Nathan Baker.
Just as against Hull on Sunday, Chelsea started with chants of 'Jose Mourinho' echoing around the ground and with a purpose which saw them take an early lead.
Oscar fed Hazard in the left side of the area and the Belgian's shot was blocked by Guzan, but only into the path of Luna who could do nothing about the deflection into his own net.
Villa also went behind after six minutes on Saturday, but feared conceding another as Chelsea maintained the intensity with which they began the game.
Yet Villa, in contrast to last December, were not as porous and try as they might, with Oscar and Hazard threatening, Chelsea could not breach the visitors' defence.
Ba, playing as a lone striker, was finding life challenging against Ron Vlaar and Clark, who had to be replaced by Jores Okore following a clash of heads with the Senegal striker.
Living off scraps, Ba shot straight at Guzan before Villa broke forward, equalising with the last kick of the half.
Agbonlahor surged by Ivanovic down the left and cut the ball back for Benteke to shoot left-footed and low into the net.
It was the sort of incisive play Mourinho demands of his teams.
The ineffective Ba was unable to make space for a shot under pressure from Vlaar as the second half resumed at a frenetic pace, with Mourinho telling his team to be patient.
Agbonlahor curled just off target from a Matthew Lowton cross-field pass and Andreas Weimann forced Cech into a save from a Benteke cross.
Mourinho lamented the disappearance of Hazard, De Bruyne and Oscar following the opening half against Hull, and again his playmaking trio's influence declined as the match wore on.
Mata, in particular, seemed to struggle to get into the game and was replaced by Andre Schurrle, when Romelu Lukaku came on for Ba.
Chelsea were fortunate not to be reduced to 10 men as Ivanovic challenged Benteke in the air and caught the Belgian with a wild arm.
Lambert, who was showing the same energy as his team in a technical area tussle with Mourinho, was furious.
Lampard hooked the ball off the foot of Okore from the resulting Ashley Westwood free-kick as Villa threatened once more, but then Chelsea struck.
Vlaar shoved over Lukaku and Lampard swung in a free-kick which Ivanovic met unopposed six yards out as all Villa's strong defensive work was undone with one set-piece.
Cech saved well from Weimann and John Terry survived a handball shout following Fabian Delph's cross as Chelsea clung on.