Wes Burns’ second-half strike secured a 1-0 victory for high-flying Ipswich against ninth-placed Derby.
The Wales international struck in the 67th minute when a Kayden Jackson effort bounced back off a post and he smashed the rebound home.
Jackson had the opportunity to make the game safe for Town from the penalty spot late on, but Derby goalkeeper Joe Wildsmith saved his effort.
The hosts had earlier penalty appeals turned down after Tyreece John-Jules went down in the box while under pressure from Nathaniel Mendez-Laing, who appeared to get a foot on the ball.
The first shot at goal did not come until the second half, but Burns put the hosts in the ascendancy with 23 minutes to play.
Wildsmith’s penalty save from Jackson in the 85th minute kept the game on a knife edge until the final whistle.
Source: Livescore