Norwich City suffered a 2-0 defeat away to Sheffield United in the Sky Bet Championship.
Harrison Burrows' double took the points away from City who were competitive in spells but struggled to create meaningful chances at Bramall Lane.
With many players unavailable, Johannes Hoff Thorup's matchday squad had a youthful look to it with several academy players named on the bench. Lewis Dobbin made a first league start for City while Kellen Fisher started in midfield.
City began brightly and won an early corner, shortly after Dobbin broke into the opposition box after five minutes before being tackled down the left side.
Rhian Brewster flashed a deflected shot wide of Angus Gunn's goal after 15 minutes, before Gustavo Hamer forced a low save from Gunn after the corner was eventually cleared.
City could have been behind after 20 minutes when former Canary Sam McCallum found himself unmarked in the area from a corner, but he dragged his left-foot shot wide from eight yards out.
A minute later and Sheffield United were ahead. City surrendered the ball under pressure and Burrows' shot from the edge of the box was tipped onto the left-hand post from Gunn before rebounding onto the other post and just over the line.
Dobbin was providing the most attacking threat for City and the winger tried his luck from distance on 27 minutes, but his shot was too high.
Hamer had Bramall Lane on its feet after 33 minutes with a speculative shot from halfway that forced Gunn to backpedal and tip the ball over the bar.
Onel Hernández drove at the Sheffield United box but his left-footed shot was comfortably off-target on 39 minutes.
Gunn made a crucial save from O'Hare on 44 minutes who couldn't steer his shot past the City stopper when put through one-on-one.
City made a fast start to the second half as Ben Chrisene played Hernández through, but his shot was blocked behind for a corner, which led to nothing.
The task became twice as hard for City when Chrisene fouled McCallum in the box and Burrows steered the resultant penalty low past Gunn to double the home side's advantage on 59 minutes.
Gunn made a remarkable reaction stop when O'Hare's shot was inadvertently steered towards goal by Shane Duffy on 68 minutes.
There was a first-team debut for Lucien Mahovo who replaced Chrisene, while Elliot Myles was introduced for Hernández for his league debut.
Callum Doyle had a pair of shots from distance in stoppage time, both of which were over the Sheffield United goal.
Seven minutes of stoppage time elapsed and City's first defeat in five league games was confirmed.
The Canaries will travel to Elland Road on Wednesday night to face Leeds United.
Sheffield United: Cooper; Gilchrist (Seriki 72), Ahmedhodžić, Robinson, McCallum (Norrington-Davies 78); Davies (Campbell 86), Peck, Hamer, O'Hare, Burrows; Brewster.
Unused subs: Faxon, Baptiste, Marsh, Oné, Blacker, Hampson.
Goals: Burrows (22, 59 pen)
Bookings: Gilchrist (50)
Norwich City: Gunn; Stacey, Duffy, Doyle, Chrisene (Mahovo 64); McLean, Fisher (Schwartau 72), Marcondes; Hernández (Myles 73), Dobbin, Crnac (Sargent 64).
Unused subs: Long, Hills, Warner, Djedje, Aboh.
Bookings: Marcondes (59), Doyle (88)
HT: 1-0
FT: 2-0
Venue: Bramall Lane
Referee: Josh Smith
Attendance: 28,239