Saturday's 2-0 win at home to Huddersfield Town also sent the Whites top and one point above West Brom. So how have the odds changed in the promotion race?
We take a look at the prices for all of the teams in the top 16 to win promotion as well as listing the odds for a top-two finish and there's a bizarre twist with Leeds.
1. Birmingham City - 500-1
Position: 16th. Points: 47. Odds for promotion: 500-1. Top-two finish: 2000-1. Photo by Gareth Copley/Getty Images. | Getty
2. Sheffield Wednesday - 500-1
Position: 15th. Points: 48. Odds for promotion: 500-1. Top-two finish: 2500-1. Photo by George Wood/Getty Images. | Getty
3. Reading - 200-1
Position: 14th. Points: 48. Odds for promotion: 200-1. Top-two finish: 1500-1. Photo by Warren Little/Getty Images. | Getty
4. Derby County - 150-1
Position: 12th. Points: 51. Odds for promotion: 150-1. Top-two finish: 500-1. Photo by Ross Kinnaird/Getty Images. | Getty
5. Queens Park Rangers - 100-1
Position: 13th. Points: 50. Odds for promotion: 100-1. Top-two finish: 1500-1. Photo by Laurence Griffiths/Getty Images. | Getty
6. Swansea City - 40-1
Position: 11th. Points: 53. Odds for promotion: 40-1. Top-two finish: 750-1. Photo by Harry Trump/Getty Images. | Getty