Ivanovic rubbed salt into Norwich's wounds when he bagged the fourth goal with 14 minutes left.
"Norwich scored a good goal and it was important to equalise quickly. From there on it was a lot of Chelsea pressure," Di Matteo said.
"The players just controlled the game. We can be happy about the performance. We are slowly evolving and don't concede too many goals."
Roberto Mancini's City sputtered through the start of their title defence and assault on the Champions League, but a convincing display at Eastlands secured a second victory in their last seven fixtures in all competitions and their first clean sheet of the season at the 10th attempt.
The hosts took the lead after five minutes when Aleksandar Kolarov curled a free-kick past Sunderland goalkeeper Simon Mignolet.
Sergio Aguero got the second goal on the hour when he steered in a Kolarov cross from close-range for his first goal at Eastlands since the dramatic strike that won the title on the final day of last season.
And England midfielder James Milner ensured City would move into second place with an 89th-minute free-kick that glanced in off Sunderland's Craig Gardner.
"In the first half we missed two or three chances, like in other games, but we had a good performance," Mancini said.
Top results
Manchester City 3 Sunderland 0
Chelsea 4 Norwich 1
Everton 2 Wigan 2
West Bromwich Albion 3 Queens Park Rangers 2
Swansea 2 Reading 2.
- AAP