Whiteleas held their nerve and were promoted from Division Two alongside champions Littletown, after their close two-wicket win at Ryhope.
Ryhope posted 156-9 declared after a blistering start of 32-0 from four overs.
Dan Douglas led the way with a tremendous 62, including 10 boundaries), backed by Sagar Udeshi (26), with dangerman Adrian Hedley dismissed without scoring. Steve Martin grabbed 4-26 in 11 overs, with Chris Nichol taking 3-32.
Set 157 to win, Whiteleas reached 32-0 before losing openers Ray McRae and Andrew Potts in quick succession. At 58-4, the game was well and truly in the balance.
But a well-worked partnership of 50 between Abdul Ameer (34) and Raja Hafiz (20) got Leas back on track.
After the Pakistani paceman was caught behind for 38 and the score on 138, it was left to youngster Alex Thomas (17no) to see Leas over the line.
Skipper Owen Peterson said: “I couldn’t be prouder for what we’ve achieved this season. The players have been fantastic since the very first game and we fully deserve promotion to the First Division”.
Third-top Peterlee had hoped to capitalise on a Whiteleas slip-up, but they went down at home to Ushaw Moor by 56 runs.
Moor had 44 runs apiece from John Southeran and Steven Milburn, plus 45 from No 9 Patrick Stephenson, as they reached 169-9.
Aaron Shellie again impressed for Peterlee (51, with six fours and three sixes), but he could not get them home after been stumped by Mark Messer, off the bowling of Jamie Robinson (4-19).
Michael Thorpe added 34, but they were dismissed for 113 to end an excellent season on a low note.
Littletown won at home to Houghton by 45 runs.
The champions batted first and made 192, with Gregg Arundel hitting 67, as Ryan Bainbridge (3-40) and Gavin Keen (3-49) bowled well to keep the score down.
When the visitors batted, Littletown’s Berwick Hall took a devastating 6-46 to bowl them out for 147. Keen top-scored with the bat (32) and Bainbridge managed 29.
Jacques Porter hit a magnificent century (102no) when Marsden batted first at Boldon CA. He was supported by Colin Mann (35) and Sam Dowens (36). In reply, Boldon CA were all out for 90, as Steven Neilson (3-6) and Mann (3-22) shone.
Murton took the honours at home to Evenwood, winning by three wickets. The visitors made 104, with Khan (40) top-scoring as Phumzile Yiba grabbed 3-16.
In Murton’s reply, opener Ricardo De Nobrega (61no) led the way, supported by Yiba (20), with Khan taking 5-13 in a devastating spell.
Langley Park batted well in knocking off 165 at home to Silksworth, for the loss of seven wickets.
In Division One, Horden finished runners-up to champions Burnopfield, when they hammered Easington by 196 runs in their derby.
Horden racked up 249-8, with Adam Dixon (46), Jamie Greenwood (35) and Lal Kumar (47) all impressing.
Gary Ward had respectable bowling figures of 3-51 for Easington, and had he not scored 32 with the bat, the hosts’ reply could have been catastrophically low.
They ended up on 53 all out, as Lewis Broom (3-22) and Carl Watson (6-17) ran rings round the batsmen.
Philadelphia secured a third-place finish with a convincing 118-run victory over Seaham Park.
Armajeet Singh hit a brilliant 104 not out and took 4-20 to claim the man of the match award. Omar Shahid (4-48 and 32) tried in vain to rally Park.
Phili posted 248-9, with Adam McGuire adding 42, before Seaham were dismissed for 130, despite Michael McNicholas’s 44, with Steve Wright bagging 3-36.
Bill Quay managed to avoid relegation when they defeated Esh Winning by seven wickets.
They only needed one point to survive for another season and they soon achieved that, when they bowled out Esh for 134, with David Earle taking 3-12 and David Hill 4-6.
Skipper Jeff Tudor (47) and Chris Little (55) ensured the victory and condemned Crook Town to relegation.
Crook did make a fist of the challenge, but it was not enough, even though they beat already-relegated Hyltone.
Andrew Pratt led the way with 64 in their total of 175, but Marlon Black (3-58) and Kit Allen, with a tremendous stint of 5-16, kept them pegged back with some excellent bowling.
Hylton, in reply, struggled to 107 all out, with West Indian bowler Black (26) top-scoring as Nathan Dawson grabbed a brilliant haul of 5-9 and Andrew Burgess chipped in with 3-48.
Burnopfield surprisingly went down at home to Dawdon by 35 runs.
The Green Drive outfit battled to post 177, with Bhavesh Patel hitting 42 and opener Steven Gale 34. Neil Killeen (4-30) and Lawrence Wood (3-31 did the damage for Burnopfield.
Only John Oswell (39) made much of an impact in Burnopfield’s reply, with Michael Hewitt (3-39), and Patel (3-25) steering Dawdon home in style.
Durham City made 184-7 against Castle Eden, with Nick Howe (30) and Danielle Hazell (37) the top runmakers. Daniel Baldwin took 3-34. In reply, Castle Eden knocked off the runs, with Philip Winpenny hitting 66 and Keith Bailey 55.