A goal just before half-time from captain Luke Chambers was sandwiched between Sears' well-taken double.
The Tractor Boys went ahead in the 29th minute when Toto Nsiala's excellent pass released Aaron Drinan on the right, and the striker's inch-perfect cross was slammed home by Sears from close range.
Sam Nicholson nearly levelled for the visitors in the 38th minute after going clear of the Ipswich defence but Tomas Holy tipped his fierce shot wide.
Alan Judge's inswinging delivery was powerfully headed home by Chambers for the Blues' second goal in the 44th minute.
Ipswich almost extended their lead in the 65th minute when Judge's terrific cross was met by Drinan but the Town forward's stab at goal was saved by Jordi Van Stappershoef.
The third goal did come three minutes later, however, Teddy Bishop's sweeping cross from the right finding Sears, who squeezed the ball under Van Stappershoef.