DUFFIELD'S second team have taken the Division One title in the Derby Area Tennis League – ahead of the club's top side.
The firsts were still at the top of the table despite their first defeat of the summer season – 7-2 at Church Broughton.
But Duffield seconds, who have also won six of their seven matches, trounced Ashbourne firsts 9-0 in their final fixture to finish with the same amount of points as Duffield firsts.
The second string clinched the title by virtue of having won 49 sets and losing 14 over the season, a difference of 35, compared to the top team's 27.
Duffield's third side, meanwhile, secured their Division Two status for next year at the expense of league leaders Burton, who they beat 5-4.
Play in Division Three concluded with champions David Lloyd 3 winning 7-2 against Ashbourne seconds, thanks to three sets from James Shepherd and Mark Knight.
And, in a tightly-contested Division Four, Melbourne remained in contention for promotion with a 5-4 win over Woodlands seconds, who are now relying on other results to save them from relegation.
In the ladies' section, the battle to avoid relegation from Division One continues between Ashbourne, Duffield and Littleover, with one side to join Woodlands in dropping down.
Littleover remain second from bottom after two straight defeats – 5-4 at Derbyshire Tennis Centre and 7-2 against Ockbrook and Borrowash firsts.
In Division Two, David Lloyd seconds claimed the title with a 9-0 win at Duffield thirds.
Duffield seconds also secured promotion with a 6-3 win at Rolls-Royce firsts, the victory coming despite Alex Higham and Emilie Ravel finishing the match unbeaten for Rolls-Royce.
Belper Meadows firsts forced their way into the Division Three promotion battle with two consecutive wins.
The 7-2 success at already-relegated Ockbrook & Borrowash thirds – Celia McKay and Pip Barfield winning all three sets – was followed by an 8-1 win over Woodlands thirds.
In the mixed section, Duffield firsts continued their Division One title push with a 9-0 win over Woodlands' top side.
Rivals Derbyshire Tennis Centre faltered with a 5-4 defeat against David Lloyd firsts, despite Mandeep Sangha and Jayne Allsop taking three sets.
In Division Two, Littleover retained their place for next year with a 6-3 win over Duffield seconds while, in Division Three, Darley Dale seconds' first win of the season – 7-2 over Little Eaton firsts – was to no avail, with both sides relegated.
Lakeside took the Division Four title and completed an unbeaten season with an 8-1 win over Duffield thirds, leaving the latter close to relegation.
Ashbourne thirds are also on the verge of clinching promotion following a 7-2 win over Ockbrook and Borrowash thirds, while Woodlands seconds moved out of the relegation zone with an 8-1 win over bottom club Little Eaton seconds.