Pep Guardiola's side were totally dominant but missing a cutting edge until Aguero's stunning half-volley finish just before the hour mark broke Palace's resolve at Selhurst Park.
A minute later Ferran Torres's clinical low shot doubled City's advantage and they could have racked up a bigger margin of victory as they turned on the style with Raheem Sterling denied by the woodwork and Joao Cancelo also going close.
With four games left City have 80 points, 13 ahead of Manchester United who host Liverpool on Sunday (Monday morning NZT) knowing that defeat would seal the title for their neighbours.
Should United draw they could still mathematically catch City but their goal difference is far inferior. If United win, City can seal the title by beating Chelsea next weekend.
In other results, Chelsea have tightened their grip on fourth place with a 2-0 win over relegation threatened Fulham, Aston Villa have moved up to ninth with a 2-1 win at Everton and Brighton and Hove Albion have pulled 10 points clear of the relegation zone by beating Leeds United 2-0.