The 22-year-old leggie took five for 17 from three overs to help restrict Otago to 81 for nine in a rain-affected elimination final in Dunedin yesterday.
The visiting side had to work hard to overhaul the modest target.
Laura Hughes helped. She clubbed 28 from 17 balls to get her side ahead of the run rate.
And Canterbury captain Amy Satterthwaite held her nerve with an undefeated knock of 30 to steer her side to a seven-wicket Duckworth/Lewis/Stern method win.
But Asmussen set up the win with her maiden five-wicket bag. Her haul was a Canterbury record, eclipsing the previous mark of four for 10 set by Frankie McKay in 2020-21.
Gabby Sullivan took two for 15 in a quality spell as well.
But Otago produced its worst batting performance of the season.
The Sparks slumped from 55 for two to 81 for nine.
"We couldn’t do it in the one that we needed to," she said.
"It was tough being on 22 after 4.2 overs when the rain came. It was a bit of a slow start but obviously, at that stage, we were expecting to bat 20 overs.
"Apparently if we hadn’t lost a few wickets we would have had a few runs added to our score with Duckworth/Lewis. That’s one of those things."
A couple of more runs may have been enough too.
The Sparks fought hard to defend what they did have, though.
Earlier, confusion probably accounted for opener Olivia Gain. She spooned a leading edge over the bowler. It found the gap, but Gain had run with the shot and was well short when Missy Banks’ throw clattered into the stumps.
Fellow opener Bella James could not get going either. She was trapped lbw for eight.
It could have been worse for the home team. Polly Inglis had been dropped on three a little earlier.
Rain interrupted play with the Sparks 22 for two.
It was a lengthy break which meant the match was reduced to 13 overs apiece.
It left the Sparks in a difficult position. They had to crack on all while trying to get re-established.
The first three overs after the rain break went well. The Sparks were scoring at 10.
But then Inglis scooped a delivery from Asmussen to cover on 26 and the innings crumbled.
Asmussen trapped Kate Ebrahim lbw for 16 to capture her second wicket in the over.
Linsey Smith chipped out for two and the Sparks had loss three wickets in seven balls.
Felicity Leydon-Davis set about trying to rescue what she could. She chipped in with 15 but lost the strike.
Asmussen picked up three wickets in the final over to complete a good match.
Canterbury will play Wellington in the final in Christchurch tomorrow.
Otago
B James lbw b Sullivan 8 (8)
O Gain run out (Banks) 0 (3)
P Inglis c Anderson b Asmussen 26 (23)
K Ebrahim lbw b Asmussen 16 (16)
L Smith c Satterthwaite b Sullivan 2 (4)
F Leydon-Davis not out 15 (12)
C Blakely b Satterthwaite 6 (6)
K Gordon c Wilson b Asmussen 2 (3)
E Black c Anderson b Asmussen0 (1)
S Oldershaw c Sharp b Asmussen 0 (2)
Extras (1b, 1lb, 4w) 6
Total (9 wickets, 13 overs) 81
Fall: 1-1, 2-17, 3-55, 4-56, 5-58, 6-78, 7-81,
8-81, 9-81.
Bowling: A Satterthwaite 3 overs, 0 maidens,
20 runs, 1 wicket, Gabby Sullivan 3-0-15-2 (1w),
M Banks 2-0-13-0 (2w), S Asmussen 3-0-17-5, A
Hotton 2-0-14-0.
Canterbury
K Anderson c Inglis b Black 0 (1)
L Hughes c Leydon-Davis b Ebrahim 28 (17)
A Satterthwaite not of 30 (32)
I Sharp c Blakely b Gordon 7 (12)
N Cox not out 14 (13)
Extras (2lb, 1w) 3
Total (3 wickets, 12.3 overs) 82
Bowling: E Black 2.3-0-18-1, L Smith
3-0-14-0, S Oldershaw 1-0-15-0 (1w), K Gordon
3-0-12-1, K Ebrahim 2-0-12-1, M Loe 1-0-9-0.
Result: Canterbury won by seven wickets
DLS method.
