Birstall secured promotion from Allrounder Bradford League Championship Two with two matches to spare after they earned a seven-wicket win over Altofts last Saturday.
There is still an outside chance Birstall could win the title but they need to bridge a 16-point gap on leaders Carlton in their remaining games.
Ryan Gray picked up 5-48 as Altofts were restricted to 155-9, despite Danny Eden making 53.
Josh Haynes led the Birstall reply with 74 and was assisted by Brad Lay (36no) to help complete a comfortable win.
Carlton also secured promotion and took another step towards the title thanks to a 37-run victory over Jer Lane, while Birstall’s top-two finish was confirmed after Yeadon suffered a 61-run defeat at the hands of Bowling Old Lane.
Spen Victoria are fourth after a 26-run victory over Buttershaw St Pauls.
Opener Sam Gatenby (48), Bilal Ejaz (41) and Michael Flathers (38) helped Spen post 184-8 despite former spinner Ben Platt picking up 6-51.
Abid Awain returned stunning figures of 8-48 in reply as St Paul’s were restricted to 155-9 despite Kevin McDermott making a battling 87.
Bottom team Adwalton kept alive their slim hopes of avoiding relegation with a four-wicket win over second-bottom Liversedge.
Vinit Patel took 5-40 as Liversedge were dismissed for 155, Sohail Hussain (53) and Qaiser Hameed (34) proving to be the best of the batsmen.
Adwalton were guided to their target by young opening batsman Josh Bennett, as he made an unbeaten 72 to ensure they collected only their second win of the season. Graham Winn took 3-32 for Liversedge.
Northowram Fields moved out of the relegation places with a six-wicket win over East Ardsley.
Hammy Shahzad (5-19) and Josh Bennett-Keer (3-22) helped dismiss Ardsley for 140 before Jacob Slater (57no) and John Lister (46no) saw them to a much needed win.
Hopton Mills dropped into the bottom three – one point adrift of Northowram Fields – after a 47-run defeat by Hunslet Nelson.
Will Stiff (82) and Sam Haigh (39) helped Nelson to 187-8 as Michael Carroll (5-33) and Ashley Mackereth (3-57) impressed but Hopton were dismissed for 140 as Glen Thompson (3-40) helped wrap up victory.