Titus Bramble struck a late equaliser to take Wigan out of the Premier League relegation zone and further dent Liverpool's faltering title hopes.
Bramble struck with a 20-yard strike after a poor defensive clearance by Liverpool skipper Steven Gerrard.
Fernando Torres had earlier put the home team ahead with a precise finish while Chris Kirkland made several excellent saves to deny Gerrard.
The result leaves Liverpool 12 points behind leaders Arsenal.
Rafael Benitez's team have a game in hand on the Gunners but their failure to win at Anfield against a team starting the match in the relegation zone does little for their title credentials.
Benitez selected Torres as the lone striker but introduced Peter Crouch and Dirk Kuyt shortly after Bramble's 80th-minute strike - a measure of the manager's desperation to collect all three points.
The Spaniard cut an animated and frustrated figure as the clock ticked down but counterpart Steve Bruce must have been delighted with his team's third away point of the season.
Bramble's strike was not only Wigan's first goal against the Reds in the top flight but also gave the Latics their first ever point off one of the 'big four' of Liverpool, Arsenal, Manchester United and Chelsea.
There seemed little hint of an equaliser after Torres's goal had finally warmed the crowd on a bitterly cold night at Anfield.
Torres had shown excellent link-up skills and his lay-off to Gerrard started the move that the Spaniard himself finished from Steve Finnan's square ball to put Liverpool ahead after 49 minutes.
There had been increasing signs of frustration from the stands and the goal seemed to ease the home side.
Gerrard almost doubled his team's advantage with a vicious free-kick that Kirkland did well to parry.
And Kirkland again foiled Gerrard after Bramble had equalised, first parrying a long-range strike and then smothering the follow-up.
Wigan went into the game having lost just one of their last four outings and were happy to compress the field of play, closing the space between the two defensive lines to try to stifle their opponents.
Michael Brown, as combative as always, almost stunned the home crowd with a well-struck half volley from 25 yards that narrowly missed Pepe Reina's goal after 19 minutes.
But after a slow start to the game Liverpool eventually found their way through the Wigan defence and forced a series of saves from former Reds keeper Kirkland.
Javier Mascherano tried to side-foot the ball home after collecting an intelligent return pass from Torres, who later played Gerrard through only for the skipper to make a poor contact with his shot.
Liverpool appealed for a penalty after Torres went down under pressure from Paul Scharner, while the Spain striker headed over from a Xabi Alonso free-kick before Torres put the home side in front.
· Liverpool manager Rafael Benitez on his team's title prospects:"We need to do almost everything perfect now but if you lose points like this it makes it more difficult.
"When you have chances you need to take them and finish the game.
"Now we need to think about the FA Cup against Luton, you cannot look at the whole season it is too long."
· Wigan boss Steve Bruce:"It gives everyone a huge lift. We were really disciplined and stuck to the game plan well.
"I have always liked Titus, he just needs a bit of confidence and he will only get better.
"It is always going to be difficult at Liverpool as they have world class players but for the last six weeks we have produced some good performances."
Liverpool: Reina, Finnan, Arbeloa, Carragher, Aurelio, Pennant (Kuyt 86), Alonso, Mascherano (Crouch 84), Kewell (Benayoun 74), Gerrard, Torres.Subs Not Used: Itandje, Riise.
Booked: Mascherano, Torres.
Goals: Torres 49.
Wigan: Kirkland, Melchiot, Scharner, Bramble, Kilbane, Valencia, Landzaat, Brown, Taylor (Koumas 79), Heskey (Sibierski 84), Bent.Subs Not Used: Pollitt, Boyce, Olembe.
Goals: Bramble 80.
Ref: Steve Bennett (Kent).