The Tractor Boys recovered from Michael Smith's curling effort from all of 30 yards to run out 3-1 winners at Portman Road.
Speaking afterwards, Jewell said: "Bristol Rovers, to give them credit, they came here and made it difficult for us. We had lots of the ball but I felt we didn't do enough with it quickly enough in the first half, I thought we passed it but we didn't really go anywhere.
"We dominated the whole match, if we're being honest, but for all the possession we had we only had one goal to show for it at half-time. Second half, we created some great opportunities and we could have won by more."
The Blues' next test is the visit of newly-relegated Blackburn Rovers in their Championship curtain-raiser on Saturday.