Celtic moved 16 points clear at the top of the Scottish Premier League with a hard-fought win over Dunfermline.
The visitors found it difficult to penetrate a determined Pars rearguard in the first half, with Kenny Miller's effort wrongly ruled out for offside.
Aiden McGeady, one of the game's better performers, gave Celtic the lead on 49 minutes with a fine curling shot.
Maciej Zurawski fired home after collecting Neil Lennon's pass before Stephen Simmons' late consolation.
Dunfermline boss Stephen Kenny made one change to the side that lost 5-1 at Kilmarnock last week, with Aaron Labonte replacing Owen Morrison, who started on the bench.
Defender Souleymane Bamba was suspended for the Pars.
Celtic defender Stephen McManus missed the trip to East End Park after aggravating a groin problem in the defeat by FC Copenhagen.
Darren O'Dea deputised in defence, while Shaun Maloney missed the game with an ankle knock. Jan Vennegoor of Hesselink was still out with a hamstring injury.
Danish midfielder Thomas Gravesen was dropped to the bench in place of Shunsuke Nakamura.
Attractive football was in short supply in the early stages as both teams struggled to come to terms with the wintry conditions in what quickly became a midfield war of attrition.
Kenny Miller missed a great chance to put the visitors ahead after 10 minutes when he failed to connect with Nakamura's cross inside the six-yard box.
Dunfermline's Stevie Crawford could not make Jiri Jarosik pay for a poor cross-field pass after quarter of an hour when his shot sailed over the bar.
Celtic were enjoying most of the possession but were failing to create many clear-cut chances.
Miller thought he had put the visitors ahead after 30 minutes but he was adjudged offside after collecting McGeady's pass and firing home.
The centre forward was thwarted again five minutes later when De Vries tipped his shot over the bar after Lennon's perfect through ball.
O'Dea's shot on the turn flew inches wide two minutes later as Celtic laid siege to Dunfermline's goal without breaking the deadlock.
McGeady gave Celtic the lead after he collected Miller's pass and sent a curling shot beyond De Vries into the bottom right-hand corner.
Celtic could have made the game safe with half-an-hour remaining when Zurawski missed a great chance from eight yards.
The Pole made amends after 68 minutes when he collected Lennon's pass inside the box and swivelled before firing home.
The Pars got a consolation in injury-time when Simmons pounced on Bobo Balde's mistake to slot the ball home from just outside the six-yard box.
Lennon and McGeady had to be separated after squaring up to each other after the final whistle.
Dunfermline: De Vries, Labonte, Shields, Wilson, Scott Morrison (McGuire 73), Ross, Mason, Simmons, Muirhead (Owen Morrison 77), Crawford, Daquin (Burchill 73). Subs Not Used: McKenzie, Hamilton, Woods, Williamson.
Booked: Wilson.
Goals: Simmons 90.
Celtic: Boruc, Wilson, Balde, O'Dea, Naylor, Nakamura (Riordan 75), Lennon (Sno 88), Jarosik, McGeady, Miller, Zurawski (Gravesen 75). Subs Not Used: Marshall, Telfer, Pearson, O'Brien.
Goals: McGeady 49, Zurawski 68.
Att: 7,080
Ref: C Thomson