The Force had generally looked the best side for most of the match, dominating possession, but struggling to crack the Highlanders defense.
They looked certain to score early in the match when they put together 23 phases as they camped on the try-line, but the Highlanders held firm in defense.
However, in the 17th minute Hayward made a break down the right and the ball ended up with Sias Ebersohn, who dived over in the corner for his first try since 2011.
Hayward converted to give the hosts a 7-0 lead and reward them for their early energy.
The two sides then traded penalties, the Force leading 10-6 at the break, until the final 20 minutes saw the Highlanders finally click into gear and produce their most cohesive rugby of the match.
They were narrowly denied a try in the 62nd minute when Ma’a Nonu slid in against the post and the video referee was called upon, but it was impossible to be certain he grounded the ball and it was ruled to have been held up.
The Highlanders had a last-gasp chance to snatch the win, but Slade knocked on.
Force captain Matt Hodgson said his team showed great resilience to hang on for the victory.
“I’m proud of the boys,” Hodgson said. “It was not the prettiest of games in the second half, but we didn’t let a try in. If we get our attack to match our defense, we will be a great side.”
Highlanders skipper Brad Thorn lamented his side’s errors.
“It was another disappointing one,” Thorn said. “It was just the little things, they are hard lessons and hopefully [at] some stage this year we will learn them.”