There was still plenty do when the England skipper came to the crease with 52 required from 31 balls, but she quickly found her rhythm.
Sciver-Brunt reverse swept her second ball from Charli Knott for four before hitting three consecutive fours off Issy Wong in the next set to bring the run rate back down to managable levels.
All-rounder Sciver-Brunt was run out attempting an ambitious second run with the scores level before Kim Garth edged one from Knott to get the Rockets over the line.
Sciver-Brunt said the decision to come in down the order was two-fold, giving some of her team-mates an opportunity to bat while managing her own fitness after recent struggles with a troublesome calf.
“We’ve probably batted quite well as a side so it was a chance for some others to have a little hit and a bit of body management as well,” she said.
The result meant the Rockets finished with 28 points and seven wins from their eight group games and cannot be caught at the top of the standings.
“We wanted to top the table and now we are looking forward to the final at Lord’s,” added Sciver-Brunt.
“Building up to Sunday we know what we need to do. There’s a couple of days to get away and refresh.”
Second-placed Brave will now wait to see whether they will face Manchester Super Giants or Sunrisers Leeds in the Eliminator.
Earlier, Maia Bouchier and Lizelle Lee shared a 49-run opening stand for Brave as they posted 117-5 from their allotted overs.
England batter Bouchier top scored with 38 off 33 balls while Lee hit five fours in her 28-ball 31 as Georgia Adams finished the pick of the Rockets bowlers with 2-14.
