De Bruyn’s score came from just 118 balls, which helped the Titans to the sizeable score of 336 for five on the first day and set them up for a hefty points haul from the innings.
Behardien and Van der Merwe then contributed a partnership of 155 for the fifth wicket to keep the Titans in the ascendancy.
Henry Davids won the toss and elected to bat first as he returned to captain the Titans, and his team made full use of that advantage.
Heino Kuhn was the only early casualty, and his demise was followed by an 80-run stand between Dean Elgar and De Bruyn that set the tone for the day.
Although the Titans were 176 for four after Elgar fell to Warriors debutant Sisanda Magala, Davids came and went for 22 and then De Bruyn was out to Simon Harmer, they were carried out of potential trouble by Behardien and Van der Merwe.
The pair maintained a steady run rate throughout their partnership, scoring at close to four an over, and were only parted when Harmer trapped Behardien lbw for 74 with three overs of the day remaining.
Van der Merwe went to stumps unbeaten on 80, while Mangaliso Mosehle has two.
Magala was the only change in the Warriors team, replacing the injured Wayne Parnell, while Davids and Juan de Villiers came into the Titans side in place of Qaasim Adams and Marchant de Lange.