Oliver Burke's first Premier League goal dented Manchester United's title challenge as bottom-of-the-table Sheffield United claimed a sensational victory at Old Trafford.
Burke's 74th-minute shot was defected past helpless keeper David De Gea by defender Axel Tuanzebe to secure a 2-1 win, just the Blades' second in the league this season.
Defender Kean Bryan had earlier headed them in front with De Gea appealing in vain that he had been impeded as he attempted to collect John Fleck's corner.
Harry Maguire looked to have dashed his former club's hopes with 64 minutes gone when he powered home a header from Alex Telles' corner to level, but United were undone once again with 16 minutes remaining as substitute Burke's drive cannoned off Tuanzebe and flew past De Gea into the net.
Thomas Tuchel endured a frustrating start to his reign as Chelsea manager as he saw his side held to a 0-0 draw by Wolves.
Tuchel, who named youngsters Reece James, Mason Mount and Tammy Abraham only among the substitutes in his first fixture, saw his side dominate, but fail to create genuine chances.
Indeed, they might even have lost had Pedro Neto's audacious scooped effort not looped on to the top of the crossbar as the visitors staged a rare second-half foray into enemy territory.
Youri Tielemans ensured Leicester's unbeaten run stretched to nine games in all competitions as they hit back to claim a 1-1 draw at Everton.
Everton playmaker James Rodriguez broke the deadlock on the half-hour, curling a superb right-footed shot beyond keeper Kasper Schmeichel and in off the post.
However, the Foxes responded and got themselves back on level terms with 23 minutes remaining when England keeper Jordan Pickford could not keep out Tielemans' low drive despite getting a hand to it, and the teams could not be split in a rousing conclusion.
Chris Wood headed Burnley to a battling victory over Aston Villa as they came from behind twice to win 3-2 at Turf Moor.
Having seconds early passed up a glorious opportunity when he shot straight at keeper Nick Pope, Villa striker Ollie Watkins made amends with 14 minutes gone when he got in front of defender Ben Mee to guide Matt Targett's cross into the net.
Villa were unable to make the most of a series of opportunities to add to their tally and were made to pay within seven minutes of the restart when Mee headed home Ashley Westwood's corner.
They regained the lead when Jack Grealish swept the ball past Pope after exchanging passes with Douglas Luiz, but Dwight McNeil levelled with 14 minutes remaining when his cross crept in and then set up Wood to win it three minutes later.
Fulham earned their first point in three games against fellow relegation strugglers Brighton in a cagey goalless draw at the Amex Stadium.
Scott Parker's men had lost their last two matches before the sides met in almost identical fashion to their 0-0 draw at Craven Cottage on December 16, and again nothing could separate the two teams.