Manchester City failed to score in the Premier League for the first time this season as West Brom frustrated the league leaders to earn a deserved draw.
City dominated possession but struggled to convert that into clear-cut chances against a well-drilled Baggies side.
Mario Balotelli came closest with a 30-yard shot that hit the bar, while Sergio Aguero wasted a superb opening.
West Brom grew as a threat and could have claimed a famous win but Jerome Thomas's drive struck the post.
The draw was a disappointing end to what has been an increasingly impressive 12 months for Roberto Mancini's side, which have seen them rewarded with a first taste of Champions League football, a first major trophy for 35 years and top spot in the table on Christmas Day for the first time since 1929.
They have accrued 72 points from 36 games in 2011, 45 from the first 18 matches of this season - as opposed to 33 from the final 18 fixtures of the last campaign - to leave them leading the division on goal difference from fierce rivals Manchester United.
Perhaps justifiably, City swaggered with self-confidence at The Hawthorns, dominating possession, but in and around the box they were given little space to work with and demonstrated a distinct lack of clinical edge.
Credit for this must largely go to West Brom, whose work rate and defensive discipline slapped the shackles on Mancini's men in a fashion few others have achieved this season.
City were reduced to shooting principally from distance, with Samir Nasri and Mario Balotelli having efforts from outside the box saved by home keeper Ben Foster, and the Italian seeing a free-kick deflected narrowly wide.
When an opening in the box did come, City's usually lethal leading stars fluffed their lines, with David Silva side-footing a first-time effort over from 15 yards after he was found by Sergio Aguero's cross.
The Argentine was himself guilty of spurning a glorious chance after the break when he broke the offside trap from a header by James Milner but paused - perhaps expecting a flag - and allowed Gareth McAuley to get back and save West Brom with a superb last-ditch tackle.
Milner himself also found space in the box as a cross was delivered from the left, but he could only tamely head wide.
With so much effort dedicated to defence, West Brom provided little threat to City, particularly for the first hour, when Chris Brunt's early shot, which flashed past the far post, and a Paul Scharner 30-yard low effort, which Joe Hart palmed wide, the closest they came to a goal.
However, West Brom fed off City's frustration and increasing commitment to attack, crafting more openings as the game wore on.
Shane Long found space at the back post from a Jerome Thomas cross but was unable to direct his header goalwards, while Brunt fired a free-kick wide of Hart's right-hand post.
Thomas came closest with a superb low drive from 25 yards that smashed into the base of the post before deflecting away from danger.
City pushed until the end to snatch a late winner, but West Brom held firm.
West Brom manager Roy Hodgson:
"It was always going to be tough. We know how good they are and we would have to be at our best. I'm very pleased that we kept our shape and discipline.
"We almost sneaked it at the end on the break, but I'm not unhappy with a point."
Manchester City manager Roberto Mancini:
"Today was difficult. We knew this before the game. When you a play a team with all players behind the ball at home, if you don't score in the first half it's not easy, you don't have any space.
"When we have a chance we should score but maybe we were too slow in the first half.
"It is impossible to score three or four goals for 38 games. There will be some moments in the year when you won't score. We did everything today and wanted to win, but couldn't."