Duffin was at the double - taking his tally for the season to 34 strikes in 33 games this term - while Willett got the other goal to make it 32 efforts in his first campaign at ninth-tier level in the Deans' 3-1 win at fellow high-fliers Brockenhurst.
Attacking ace Duffin has now set a Horndean record of 33 Wessex Premier goals in a season, surpassing the previous high of 32 set by Graham Lindsay in the 2007-08 season.
But despite the ferocious pairs flurry of goals across the campaign, Birmingham stated 'humble' duo are both still chasing the individual targets they set for themselves.
The Deans boss said: ‘They believe in their ability, they also believe in the people behind them who are giving them these opportunities to score goals as well.
‘They’re confident boys who believe in their own ability. They’re two very, very humble players as well. We set targets in-house and Connor Duffin or Zak Willett have not hit their target yet. By the way, these players set their own targets.’
Second-placed Horndean, facing Brockenhurst in the league for the second time in the space of just eight days after last weekend's stalemate at Five Heads Park, went ahead through Duffin's drive which found the bottom corner on nine minutes.
The Deans, now six points better off than Brock having played a game more as their opponents dropped down to fifth in the table following the defeat, had a a second through leading scorer Duffin just seven minutes later.
Willett, himself now on 32 goals for the season after signing from Hampshire Premier League Paulsgrove last summer, put Horndean in complete control, making it 3-0 just two minutes after the restart.
Mitchell Speechley-Price pulled one back for Brock two minutes past the hour mark but the Deans held out to claim a 3-1 success to make it 22 Wessex Premier wins this season.