It was the visitors, who ply their trade two divisions below Ipswich, who took the lead when right-back Michael Smith cut in onto his left foot and found the top corner with a powerful effort.
The Tractor Boys got back on level terms five minutes before the interval when Jason Scotland collected the ball outside the area and drove at the Rovers defence before finding the bottom corner with a low strike.
The home side came out firing at the start of the second 45 and were awarded a penalty when Adam Virgo upended Luke Hyam. Chopra stepped up but saw his high spot kick well kept out by Sam Walker.
The hosts sealed the win six minutes from time when left-back Aaron Cresswell nodded home after Walker could only beat away an Emmanuel-Thomas curler.
The Tractor Boys begin their league campaign against newly-relegated Blackburn Rovers on Saturday, while Rovers welcome Oxford United for their league curtain-raiser.