Leeds United's unbeaten start to the Championship season was ended by Millwall, as Wolverhampton Wanderers won at Nottingham Forest and Cardiff City snatched a last-gasp draw with Sheffield Wednesday.
Preston North End is just two points off the top after a second win on the spin, while Ipswich Town moved back into the play-off positions with a victory over Bolton Wanderers.
Sheffield United's three-match winning streak was ended by Norwich City, but the Blades cling on to a spot in the top six with Middlesbrough and Bristol City closing in.
Leeds had made a brilliant start under boss Thomas Christiansen this season, but was beaten at the eighth attempt at as Aiden O'Brien fired home 17 minutes from time to earn a deserved three points for Millwall at The Den.
Wolves followed a pulsating midweek 3-3 draw against Bristol City with a 2-1 win at Nottingham Forest that leaves Nuno Espirito Santo's men second.
Diogo Jota was the hero with a second-half double either side of Mustapha Carayol levelling the scores for Forest.
Cardiff was on the brink of a second straight defeat as Gary Hooper made it four goals in four games with a powerful header from a flowing Wednesday move in the first half, but Sol Bamba's last-minute leveller left Cardiff level with Leeds and Wolves on 17 points, while the Owls drop to ninth.
Chris Wilder was sent to the stands as the Norwich City won 1-0 at a Sheffield United side that had started the day in third. The Blades will now look to recover in next week's Steel City derby at Wednesday.
Daniel Johnson, Jordan Hugill and Tom Barkhuizen all scored as Preston, which is fourth, ran out a 3-1 winner at Birmingham City, while Bolton Wanderers remains winless this term after going down 2-0 at fifth-place Ipswich Town.
Britt Assombalonga scored the winner as Middlesbrough twice came from behind to beat Queens Park Rangers 3-2 and move within a point of the play-offs, while Bristol City is eighth after battering Derby County 4-1.
Sunderland appeared on course for just a second league win of the campaign before David Meyler's 82nd-minute strike earned Hull City a 1-1 draw.
Burton Albion did secure a second league win, however, with a 2-1 triumph at home to Fulham, while Brentford drew 1-1 at home to Reading.