Liam Delap's exceptional goal-scoring display helped Ipswich earn their first home win of the season as Chelsea's title hopes dwindled.
After scoring a 12th-minute penalty, the 21-year-old striker set up former Chelsea winger Omari Hutchinson's second eight minutes after the break.
Chelsea dominated possession but were wasteful and the video assistant referee (VAR) ruled out a Joao Felix first-half equaliser after a long check for offside.
Earlier, ex-Manchester City striker Delap powered in a penalty that he won himself after VAR judged that there was "sufficient contact" by goalkeeper Filip Jorgensen after the Ipswich man had dribbled past him.
Delap later capitalised on Axel Disasi's poor back pass to set up Hutchinson to make it 2-0.
Ipswich's win puts them above Leicester City into 18th and just one point behind Wolves in the table as they look to move out of the bottom three.
Chelsea have now lost consecutive matches following the goalless draw at Everton that ended an eight-match winning run in all competitions, and they remain fourth in the Premier League.
Enzo Maresca's men are 10 points behind league leaders Liverpool - with Arne Slot's pace-setters also having a game in hand - leaving a sustained title challenge looking unlikely.
Line-ups
Ipswich Town XI: Sam Morsy, Christian Walton, Wes Burns, Nathan Broadhead, O'Shea, Jens Cajuste, Luke Woolfenden, Leif Davis, Jacob Greaves, Liam Delap, Omari Hutchinson
Subs: Conor Townsend, Sammie Szmodics, Conor Chaplin, Kalvin Phillips, Ben Johnson, Arijanet Muric, Jack Clarke, Ali Al-Hamadi, Jack Taylor
Chelsea XI: T.Adarabioyo, Marc Cucurella, Nkunku, Axel Disasi, Felix, Cole Palmer, Noni Madueke, Filip Jørgensen, Enzo Fernández, Moisés Caicedo, Levi Colwill
Subs: Sancho, Reece James, Robert Sánchez, Pedro Neto, Malo Gusto, Nicolas Jackson, Josh Acheampong, Renato Veiga, Marc Guiu
Yungswag20
246
Chelsea coach said he is not a title contender. Some fan thought he was joking
Doxmang
123
Chelsea 0-0 Everton Chelsea 1-2 Fulham Ipswich 0-2 Chelsea They thought they were back😜😀🤝
fupceiluyz
112
Those plastic fans who have been telling Maresca to start Nkunku and Felix must shut up forever.😡😡😡😡😡😡
Fris
91
They said they are not title contenders... they just want to win every match. At least they've got their wish. You cannot reject the cup and expect to win every match.
Nino_Luxury
56
Another day to preach to my fellow Chelsea fans that Chelsea was built around Jackson and not Palmer, if you are going to bench the only man that presses then you gotta bring in real defense, not what we currently have. I didn't bother to watch this match because Jackson wasn't playing, I knew we were about to be embarrassed by a Championship side 😂💙. We can't even seal a 15 minutes game without Jackson without conceding a goal, and you want me to believe that you can play a full EPL game without him, the only man that absorb pressure for others to thrive. There will be no Palmer without him or other player without him, the match will never settle. Enzo, continue your experience with this your Nkunku guy
Clintntale
54
cole plamer still waiting for a Chelsea penalty
Carolme
32
Click this to view GIFs: http://www.goalgif.xyz/v2/live/matchGifs?match_id=53877033&language=en
Arsenal1400
26
Don't worry we are back together donating 3 points