West Brom returned to the top of the Sky Bet Championship despite being held to a goalless draw by Birmingham.
The Baggies drew a blank as they made their comeback after the three-month enforced break due to the coronavirus pandemic.
They moved above Leeds on goal difference but will see it as a chance missed after dominating their local rivals at an empty Hawthorns.
Matheus Pereira fired wide in the closest Albion came but they failed to score for a third straight league game.
Title rivals Leeds travel to Cardiff on Sunday and will retake top spot if they avoid defeat in Wales.
Albion still moved seven points clear of third-placed Fulham, who lost to Brentford, in the race for automatic promotion with eight games left.
Birmingham remain 16th after a gritty point in their first game back with boss Pep Clotet having announced last week he will leave at the end of the season.
They were on the back foot for much of the game and Jake Clarke-Salter's excellent block on Matt Phillips denied Albion early.
The hosts dictated the play but failed to stretch Birmingham - who named eight academy prospects on the bench - enough to make a first-half breakthrough.
The steely visitors were organised at the back but one-dimensional going forward as highly-rated Jude Bellingham struggled to impose himself.
Callum Robinson headed wide at the far post five minutes before the break in a rare opening of a largely forgettable first half.
Albion tried to up the tempo after the break and Phillips saw a volley deflect over before Hal Robson-Kanu just missed Pereira's cross.
Winger Pereira will now complete a £8.25million move from Sporting Lisbon after playing in his 30th game for the Baggies, triggering a clause to make his loan permanent.
His influence began to grow and Pereira drilled just wide after 67 minutes having already seen a free-kick blocked by the wall.
Ultimately, Albion could not find a way through and it was Birmingham who wasted the best chance of the game with six minutes left when Scott Hogan planted a header straight at Sam Johnstone.
What the managers said...
West Brom's Slaven Bilic: "I'm not happy but even the table looks better now. Every game is a potential three points, I'm disappointed with the result and that we didn't get it but there were a lot of positive things considering it was our first match back.
"Of course it was a missed opportunity and I'm not happy with the result, I'm disappointed with the result. We deserved to win and we did enough to win. You have to be good enough in the final product. The number of shots and crosses we had were extremely high. It comes down to sharpness, you need matches to get sharp. Everything else was there and there are a lot of positive things."
Birmingham's Pep Clotet: "As it's the first game we've played after three months the last thing I wanted was an open game. In an open game would have given them too much advantage. Tactically the team was superb and we had a couple of chances. West Brom had a lot of domination but both teams were as good as each other when it came to the final third.
"With the difference of the teams and in circumstances we played the right game. Our mentality doesn't change, we try to fight for three points every game. I hope this is enough and I'm sure it's going to be very crucial, the 90 minutes we played, because we have a game under our belt."