Leicester go third with win at Palace
Turkey centre-back Soyuncu, who joined from Freiburg in 2018, has been one of the shining stars for the Foxes this season and further endeared himself to their fans with a stooping header that broke the deadlock in the 57th minute.
Jamie Vardy, who scored a hat-trick in the 9-0 win at Southampton, then sealed the away win in the 88th minute with a first-time strike after a swift one-two with substitute Demarai Gray.
Full-back Ben Chilwell came close to adding a third in stoppage time but saw his angled strike come off the inside of the post.
Up until the first goal the fixture, which had yielded nine goals in the previous two encounters, had been a tight affair.
Vardy had an angled shot saved by Vicente Guaita and the Palace keeper did brilliantly again to snuff out the danger after the striker had got between his central defenders.
Mid-table Palace, who came into the match with seven points from 12, failed to trouble Kasper Schmeichel aside from a Jeffrey Schlupp deflected strike that had to be tipped over the bar by the Dane.
The Eagles remain ninth with 15 points while Palace are level with Chelsea on 23 points, but with a better goal difference, and just two points behind second-placed Manchester City.
Maddison and Tielemans sparkle again
You cannot blame lifelong supporter Leigh Herbert for again backing Leicester to produce their second 'miracle' in four years.
He believes they are a stronger unit than the one that stormed to the 2015-16 title and earned him £20,000 for his 5,000-1 bet.
The bookies agree with Leigh and gave him odds of 300-1 this time, although perhaps a better bet is to back them to finish in the top four.
This season those heavily used tactics that brought so much success five seasons ago are proving fruitful again.
In James Maddison and Youri Tielemans they have a duo in tune with Vardy's intentions in the same way Danny Drinkwater and Riyad Mahrez were in the title-winning season.
Maddison found the former England striker for the first chance which Guaita did well to save before Tielemans threaded a brilliant ball into Vardy's path, only for the Spanish keeper to anticipate the danger.
Midfielder Maddison had another outstanding game. He had a direct hand in seven of Leicester's first eight shots in the match before delivering the corner for Soyuncu's opener.
When called upon to defend, centre-backs Soyuncu and Jonny Evans, who made one notable block to deny Wilfried Zaha, coped comfortably.
Gray's introduction in the 74th minute added more pace to the attack and he linked up with Vardy in the area for the second, which effectively ended the contest.
It is Arsenal at home next Saturday for Leicester, but thoughts might already be fixed on back-to-back fixtures with Manchester City and Liverpool in December.
Palace struggle in attack once more
As for Palace, they performed their own miracle under Roy Hodgson when he took over just over two years ago with the team in a desperate state.
Now the 72-year-old football sage is hoping for an extension to his contract, which few would argue he has not earned.
This season his side had only lost once at home prior to Sunday's fixture and came into the match having come from 2-0 down to draw to 2-2 at Arsenal.
But there was to be no fightback against the Foxes as once again Palace's seemingly perennial problem in the final third reared its ugly head again.
Schmeichel only had to stretch once to ensure Schlupp's shot did not embarrass him as the home attack struggled to make breakthroughs.
Palace have only scored 10 goals this season - the joint second worst total in the Premier League and the same number as Vardy.
Hodgson might be advised to ask for funds for a new striker during his contract negotiations.