Fire slip to 40-4 and fail to pick up the pace as they post 100-8
Rockets start slowly but Villani hits a superb unbeaten 55 off 40 balls and Du Preez adds 32* off 20
Rockets win by eight wickets with 18 balls to spare and go ahead of Phoenix into third and final knockout spot
Phoenix play game in hand against Spirit on Tuesday
Fire finish with one win from their six matches
Tuesday's matches: Spirit v Phoenix women (15:00 BST) & men (18:30 BST)
Trent Rockets spinner Alana King to Sky Sports: "We're really happy. We had a simple plan of attacking the stumps and we stuck to that for the majority of the innings and we're very happy to restrict them to 100.
"We knew that the pitch was playing a bit slower and keeping low so we just had to bring the stumps into play as much as possible.
"We'll be brave [with the bat] and try and play to our strengths."
Nikesh Rughani
BBC Radio
Brunt, with all her experience, just rolls her fingers on that. Nicely done.
Filer b Brunt 14 (Fire 100-8)
A wicket! Katherine Brunt gets the slower ball right this time.
Lauren Filer, understandably, gives herself some room to go for the big heave. But it is you miss, I hit time as the ball clatters into the stumps.
Claire Nicholas gets a single off her first ball to bring up the Fire's 100. That's something at least.
What will the final ball bring?
Lydia Greenway
Former England batter on BBC Radio
That goes down as poor cricket all around. Carey will not be happy getting out on that ball, and obviously, Katherine Brunt will not have wanted to execute the slower ball like that.
Carey c Villani b Brunt 27 (Fire 99-7)
That will be a no.
It's a horrid ball from Katherine Brunt. It is an attempted slower ball that turns into a low full toss. Carey though gets the shot all wrong and the ball loops into the hands of Elyse Villani.
What a shot. Lauren Filer where have you been?!
It is just back of a length from Katherine Brunt and Filer plays a wonderful cross-batted swiped down the ground for four.
A single then brings Nicola Carey back on strike. Carey is 27 from 28. Can she add to that tally in the final three balls?
Nikesh Rughani
BBC Radio
These are bonus runs for Welsh Fire. The keeper was totally wrong-footed and she is no longer standing up to the stumps now.
And another! This is a tad fortunate though as an under-edge from Lauren Filer flies past the wicketkeeper and races down for four.
Katherine Brunt will bowl the final set.
A boundary! At last! It is good footwork from Nicola Carey as she middles one off Nat Sciver and the ball disappears past deep mid-wicket for four.
The first boundary since the 23rd ball.
Lydia Greenway
Former England batter on BBC Radio
Great spell from Alana King. So nice to have a player like that in your line-up, someone you know will come in and bowl tight lines. She has been a shining light for the Rockets, also hitting some handy runs.
Image source, BBC SportAlana King is bowled out. She finishes with figures of 1-10 from 20 balls. Masterful bowling.
10 balls left. Can Welsh Fire even get to triple figures?
Lydia Greenway
Former England batter on BBC Radio
I think spin to finish the innings, or majority of the innings, is the way to go from here. The gap between runs and balls is only widening.
Nicola Carey is looking to take the initiative but just cannot find the middle of the gap. She is trying everything, including a reverse sweep, but the ball goes straight to the fielder.
Alana King bowled a wicket maiden - her third maiden of the tournament.
Fantastic bowling.
Nikesh Rughani
BBC Radio
What a catch that is! Running in 25 yards from the boundary, with a full-length dive. That was all about the catch from Bryony Smith.
George c Smith b King 0 (Fire 74-6)
What a catch Bryony Smith!
Katie George doesn't play the support role, she dances down the pitch and goes for the big hit. But Smith runs in from the boundary and takes a wonderful catch diving forward at full stretch.
Lydia Greenway
Former England batter on BBC Radio
I think if Welsh Fire can get up to a 115 or so, they can give their bowlers something to bowl at. But as I said earlier, they don't have pinch hitters, someone to just come in and give it a whack.
Image source, BBC Sport