The 30-year-old former Crystal Palace and Birmingham City player, who played his football in Greece last season, lined up against his old club Town, who ran out 3-0 winners in front of a crowd of 3,519 at the Weston Homes Community Stadium.
Colchester performed well in a goal-less first half, with Freddie Sears and Dan Holman both going close before the break.
But Town had their chances too, with Paul Anderson squandering the pick of their chances when he headed wide unmarked at the far post from Frank Nouble's deep cross.
Ipswich took the lead ten minutes after the break through Nouble, who made no mistake from 12 yards after Daryl Murphy had picked him out in the area.
And Nouble doubled Town's lead two minutes later when he headed home Anderson's deep cross unchallenged at the far post.
A superb reaction save from Ipswich keeper Bartosz Bialkowski denied Ambrose a goal against his former club just before the hour mark, as both managers made a succession of substitutions in the second half.
Ipswich added a third goal with 13 minutes to go when Jack Marriott drilled a fine low shot past U's keeper Sam Walker from nearly 25 yards
For a full match report, pictures and reaction to Colchester's friendly with Ipswich, see Thursday's Daily Gazette.