First five-eighth Fletcher Smith, who played a key kicking game, missed the subsequent conversion.
Moments later, Taranaki were on attack and first five-eighth Stephen Perofeta broke the line to put the visitors in a positive position. Midfield back Teihorangi Walden ran straight and broke through two Waikato defenders to even the ledger. Perofeta's conversion was then charged down.
After Smith was denied in the corner, moments later wing Declan O'Donnell, who played 20 games for Taranaki, scored for Waikato. Smith was able to add the extras giving the home side the 12-5 lead.
The scores were level again when Taranaki centre Sean Wainui scored under the posts. It was touch and go for Taranaki supporters as referee James Munro checked with television match official Lee Jeffery if there was any obstruction. The try was awarded, and conversion added.
Waikato took a 19-12 lead at the break as Samisona Taukei'aho picked off the back of a ruck to score.
Playing with a stiff breeze at their backs, Taranaki levelled the scores again as Number 8 Pita Gus Sowakula, playing on his home Super Rugby ground, picked up from the back of the scrum to charge over.
That's all the points Taranaki could manage in the match as Waikato took firm control.
Promising centre Quinn Tupea scored at the other end after Taranaki's defence couldn't contain him.
Lock James Tucker crashed over in the corner after a kick from Smith wasn't collected in the backfield.
A lapse in concentration by the Taranaki defence allowed Alaimalo to score his second try that finished off a strong performance by the Mooloos.
Adding to Taranaki's woes, Waikato retained the Ryan Wheeler Memorial Trophy and bounced back from a four-game losing streak in the competition.
At a glance:
Waikato 38 (Tries:Solomon Alaimalo,2, Declan O'Donnell, Samisona Taukei'aho, Quinn Tupaea, James Tucker, Conversions: Fletcher Smith,4).
Taranaki 19 (Tries: Teihorangi Walden, Sean Wainui, Pita Sowakula, Conversions: Stephen Perofeta,2).
Half Time: 19-12