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.
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.
3. Reading - 200-1
Position: 14th. Points: 48.
Odds for promotion: 200-1. Top-two finish: 1500-1.
Photo by Warren Little/Getty Images.
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.
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.
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.