Consistent possession inside Mid Northern's half eventually led to Baigent's second, giving Hora Hora a first-half lead of 15-6 - despite Mid Northern controlling the last five or so minutes deep inside Hora Hora's half.
Substitute winger Wendt, on for Dougie Te Puni, was quick to stamp his mark on the game - finishing off out wide after Fosita re-gathered a chip and chase and spread the ball out wide to make it 20-6 five minutes into the second half.
Wendt was back in the meat again soon as Hora Hora brought back the old school rolling maul before attacking down the short side, with simple drawing and passing being enough.
At 27-6 with 20 minutes remaining, Mid Northern needed to get a wriggle on but weren't having proceedings go their way as Hora Hora dominated play and kept putting the points on the board - essentially edging themselves into the finals.
Mid Northern did manage a late surge as Buster Tahere charged down a Fosita clearing kick from the restart to make it 30-11. But, in the end, ill discipline squandered any chances of closing the score late in the game.
Hora Hora coach Doug Te Puni agreed his side had been impressive considering the conditions, saying the handling abilities were surprising.
"We talked about keeping it tight but the guys started seeing holes out wide so they decided to have a crack.
"When you've got a Northland first-five, second, and centre, they know how to draw and pass and finish off.
"The guys all believe in what we believe and it was a great team effort, everyone just does their part - it's like a well-oiled train. We've all got that team thing going and we're all buying into it."
Meanwhile in the weekend's other semifinal, Wellsford closed out the game against Mid Western 24-21 - continuing their tight battles from throughout the season.
The two teams have pretty much been inseparable this season, with Wellsford having the wood over them in all three encounters - winning 29-27 in April and 8-7 in June also.
Southern Districts Premier Grade semifinals
Hora Hora 30 Mid Northern 11
Wellsford 24 Mid Western 21
Southern Districts Premier Reserve Grade semi finals
Western Sharks 22 Wellsford 15
Mid Northern 26 Kamo 27