Birchfield Harriers overcame a fixture clash with the AAA's Under-23 and junior championships at Bedford to score 387 points in the Midland Women's League match at the Alexander Stadium and beat second-placed Charnwood Harriers by 42 points.
The destination of the title will go down to the wire at the last match in Rugby on August 21. Birchfield and City of Stoke are joint first, with 12 points, but Birchfield, led by Lyn Orbell, hold an advantage of 68 match points over their Staffordshire rivals.
Zoe Derham, who represented England in the hammer competition at the Commonwealth Games in Manchester in 2002, accomplished two victories.
The 24-year old won her speciality discipline with an effort of 62.44 metres, threw the discus 35.87m and was second in the shot with a season's-best put.
Jessica Palmer stepped up from the under-17 age group to win the senior B string discus.
The 1998 Commonwealth Games 4x400m relay medallist, Michelle Thomas, won the one-lap race in 55.8secs and the B 200m in 25.4secs.
Debbie Rowe continued her comeback from injury with victory in the triple jump with a distance of
12.31m while Lizzie Patrick won the B string to secure maximum points for the Perry Barr club.
Warwickshire champion Hilary Smith and Carrin Myers, of Kingstanding, repeated this feat in the pole vault and 14-year old Ejiro Okoro won the under-17 800m in 2:22:2.
Twin sister Ese won the 300m hurdles in a careerbest 45.5secs and was second in the 80m hurdles. Joanne Caulton won the 300m in 42.2 secs and the B 300m hurdles. n Olympic champion Yelena Isinbayeva, of Russia, broke the women's pole vault world record at the IAAF Super Grand Prix meeting in Lausanne, Switzerland last night.
She cleared 4.93 metres to break her own previous record of 4.92m set in Brussels last September.
Briton Nathan Douglas produced an encouraging performance to finish fourth in the triple jump.
Douglas, who set a personal best of 17.11m in Bratislava last month, raised it to 17.27m with a splendid early- round effort.
The performance moved him into sixth place on the UK all-time list ahead of his bid to gain selection for the world championships at this weekend's trials in Manchester.