Barnsley came from behind thanks to Finnish defender Aapo Halme's 90th-minute equaliser at Oakwell as they drew with West Bromwich Albion for the second time this season.
But the point for the Baggies, now unbeaten in 14 games, ensured that they would remain top of the Championship, no matter how Leeds United fared in their late kick-off at home to Preston.
As it is, after Leeds matched their 1-1 draw, Slaven Bilic's side ended Boxing Day as they had begun it, still three points clear, but with a slightly reduced gap to the chasing pack, 11 clear of third-placed Brentford.
Struggling Barnsley showed what they are capable of when they led 2-0 at the Hawthorns earlier in the season, only to be hit by two late Albion goals in a 2-2 draw. But this time the boot was on the other foot when West Brom led before Halme met Conor Chaplin's cross to level from close range and earn a deserved point.
Albion, who have not won at Oakwell since August 1947, looked on course to put that right when they scored after just five minutes thanks to a real Christmas gift from Barnsley goalkeeper Samuel Sahin-Radlinger.
Filip Krovinovic had not scored in over two years, since a 3-1 win for Benfica against Estoril in December 2017
Sahin-Radlinger's miscued his left-footed clearance straight to Filip Krovinovic. And, from 30 yards out, the Croatian midfielder cashed in, coolly returning it back over the Tykes keeper's head.
Summer signing Krovinovic's first goal for Albion - his first in over two years - made him the 15th different Albion player to score this season.
It looked set to earn a ninth win in 13 away games, but battling Barnsley's pressure finally told as Albion were forced to settle for their second 1-1 draw of the festive season.
After the hosts had the better of the chances in the first half, the Tykes were so close to levelling when Jacob Brown's volley was kept out by a wonder save from Sam Johnstone, who also kept out a Luke Thomas curler after the break.
On a day when relegation rivals Luton Town and Wigan Athletic were both denied victory by injury-time equalisers and Stoke City won late on, Halme's leveller at least prevented Barnsley from slipping to the foot of the table.
But it could not prevent Albion from stretching their unbeaten streak to the club's best in the league in well over a century - since a 17-match run without defeat from December 1901 to March 1902.
Barnsley boss Gerhard Struber:
"West Brom were, as expected, a difficult team as league leaders but, after this game, I am very happy with this team. We were the better team with the better chances.
"I feel good. I am very happy with our performance. We were very disciplined and created a lot of chances. We had the right mentality and character and right match plan.
"We are not a relegation team. The points will come if we have the attitude like this. We have the right mentality to win games.
"A young team we never give up and with this attitude we can beat opponents. We have the right quality and also the right character to stay in this league."
Albion head coach Slaven Bilic told BBC WM:
"Of course I am disappointed when you concede late and not get the three points but they did create a lot of chances in the second half.
"We knew it was going to be hard because they've recently got a really good record and are playing good football, especially at home.
"Barnsley are a good team. They run a lot and they came into our box with four, five or six players. But I expected us to be more clinical.
"It is a sticky period, I'm never happy with a point but we have to take it. When we conceded, we were disappointed but, to be fair, they deserved it."