Leicester cruised to a 3-0 win over Newcastle at St James' Park after the hosts were forced to play most of the second half with 10 men due to injuries.
Newcastle sat deep early on and allowed the visitors, who had a staggering 77 per cent possession, to pass along their defensive lines. But former Magpies forward Ayoze Perez capitalised on a loose pass from Florian Lejeune in the 36th minute to open the scoring.
Lejeune produced another shocking loose ball three minutes later and Perez intercepted again, threading a pass to James Maddison, who smashed a 25-yard rocket past Martin Dubravka.
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- Newcastle: Javier Manquillo and Yoshinori Muto were handed starting berths, with Andy Carroll and DeAndre Yedlin among the subs.
- Leicester: Ben Chilwell, Caglar Soyuncu, Youri Tielemans, James Maddison, Ricardo Pereira and Wilfred Ndidi all returned to the starting XI, James Justin, Wes Morgan, Demarai Gray, Marc Albrighton and Hamza Choudhury dropped to the bench.Jamie Vardy missed out with a calf injury. He missed the West Ham match after his wife gave birth to their daughter.
Two goals down, Steve Bruce's woes were compounded with three quickfire injuries to Jetro Willems, Javier Manquillo and Jonjo Shelvey, resulting in all substitutes being used by half-time, while DeAndre Yedlin also broke his hand but completed the full 90 minutes.
Fabian Schar then pulled up with a hamstring injury just five minutes into the second half and Newcastle were down to 10 men, although they did not concede again until the 87th minute when substitute Hamza Choudhury hit a stunning third for the Foxes.
Newcastle: Dubravka (7), Schar (5), Shelvey (6), Joelinton (5), Muto (5), Hayden (5), Willems (5), Fernandez (5), Manquillo (5), Lejeune (2), Almiron (5)Subs: Krafth (5), Yedlin (5), S. Longstaff (5) Leicester: Schmeichel (6), Chilwell (7), Soyuncu (7), Evans (6), Tielemans (7), Maddison (7), Iheanacho (6), Perez (7), Pereira (7), Ndidi (7), Fuchs (7) Subs: Morgan (6), Gray (7), Choudhury (7)
Two howlers & five injuries
Newcastle failed to engage as Leicester dominated possession early on in their defensive and middle thirds, maintaining defensive banks to prevent space for the Foxes' customary fast breaks.
But that game plan was shattered when Lejeune made a poor pass across his own penalty area for Perez to intercept, and he found the back of the net as he tumbled from a Schar's desperate lunge.
Having only started three league games this season, Lejeune produced another hospital ball minutes later into the path of a ruthless Perez, with Maddison completing the turnover by despatching past Dubravka in emphatic fashion.
The injuries that followed quashed any chance of a Newcastle recovery, but still Leicester struggled to carve clear-cut chances in front of goal and Steve Bruce's side may well have hung on without the costly errors and a more clinical edge.
The Magpies should have been ahead on 25 minutes after Shelvey launched a pass over Leicester's defence, but Joelinton looked sluggish waiting to shoot, allowing Caglar Soyuncu to intervene and his shot bounced off Kasper Schmeichel.
The loss comes after back-to-back defeats against Manchester United and Everton and now marks a clear dip after a sustained period of form going into the festive period - but the four injuries could prove far more costly than the result.
Analysis: Injuries will intensify debate
Sky Sports' Nick Wright
Premier League managers from Jose Mourinho to Pep Guardiola have been queuing up to criticise the packed festive fixture schedule recently and there was more evidence of why on New Year's Day as a string of players from clubs up and down the table succumbed to injury.
Newcastle were the worst hit, but they were not the only ones affected and, with many Premier League sides already coping with long absentee lists, the debate over the festive fixture schedule is sure to intensify following the third round of Premier League games in just six days.
The Premier League have introduced a February winter break this season, which will take place across two weekends, but that is little comfort to sides already decimated by fatigue-related injuries. Leicester boss Brendan Rodgers summed up the views of his counterparts last week. "It's 'Let's pretend to have a break'," he said. "It's disappointing to say the least."
What the managers said
Newcastle manager Steve Bruce
"I've been involved in the game for 40 years but I've not seen anything like that. We lost four players in 20 minutes and gifted them two goals.
"You get injuries by forcing players to play tired. That's not an excuse, it's a fact. I was concerned before the match, I made that clear.
"You don't want it to happen that way. It could have been five we lost because Yedlin broke his hand, he manfully played on. In all the years I've been involved I don't think I've been involved in a crazy 15 minutes like that.
"I said it a month ago that to ask players to play four games in 10 days is ludicrous. Today is the consequence."
Leicester manager Brendan Rodgers
"We played very well, particularly in the first half. We really attacked the game when we had the ball and when we didn't have the ball, and that led to two really good opportunities for us.
"The first goal, we press it, Ayo anticipates it really well, cuts it out and then shows great skill to finish.
"The second goal as well, we press it, win it back, and then it's a great bit of individual quality from James to score. I thought we were well deserving of that in the first half.
"Unfortunately for Steve and Newcastle, they [lost Schar though injury] at the beginning of the half, but then I was really pleased with our game idea then because we were happy to have the ball, work them side to side and wait for more openings. They came, we just couldn't quite finish.
"But then we get the third goal through a great finish by Hamza and it rounded off a good day for us."
Man of the match - Ayoze Perez
Perez ran the show against his former club, pouncing on both of Lejeune's errors for the game-changing goals, to score the opener, assist Maddison and create a match-topping four chances.
Youri Tielemans also produced a dazzling display, while Christian Fuchs, Wilfred Ndidi, Soyuncu and Maddison all worked tirelessly to control the game and ensure three points against weakened opposition.
- Newcastle have lost three Premier League games in a row for the first time since October 2018 under Rafael Benitez.
- Leicester averaged 77.1% possession versus Newcastle - their highest such figure in a Premier League away game since the start of 2003-04.
- Since the start of last season, Leicester's James Maddison has scored eight Premier League goals from outside of the box; more than any other player.
Newcastle travel to Rochdale in the third round of the FA Cup on Saturday before facing Wolves at Molineux the following weekend.
Leicester have a hectic week ahead, hosting Wigan in the FA Cup in three days' time, facing Aston Villa in the first leg of the Carabao Cup semi-final at the King Power on Wednesday and facing Southampton on home soil next weekend.