His success in the latest Yorkshire Order of Merit competition saw him card rounds of 74 75 for a five-over aggregate.
The youngster had to overcome a faltering start, after bogeys at the first two holes, hitting back quickly at the fourth with a birdie.
Further birdies at eight and 12 sandwiched a bogey on 10 and two more bogeys left him in a tie for the lead at halfway.
With Dave Wormald on his bag in the afternoon, Bromley birdied the fifth after two bogeys and then played excellent golf to reel off eight straight pars. As the wind strengthened two more shots were shed, but he closed with three pars and edged club-mates Andrew Stringer (76 74) and Dave Robinson (74 76) by one.