The spinner shuffled and hooked the ball for a boundary to equal Canterbury's dig of 286 runs.
All Patel had to do was eke out a single from the two remaining balls as captain William Young and coach Heinrich Malan must have uncoiled their bodies from their perch, if they hadn't already got up from all the tension.
The country's top domestic red-ball spinner, for the past three seasons, was just as adept at delivering with the bat when push came to shove.
The result yesterday was the sort of stuff Burger King Super Smash Twenty20 competition organisers dream of.
It was one for the table-topping Stags to savour, with a ball to spare, after losing the T20 grand final a fortnight ago.
"That was a very good win against a very good Canterbury side," said opening batsman Ben Smith, who spearheaded Stags' run chase after the visitors won the toss and elected to bat.
Smith, who scored 82 runs from 111 balls, including 10 fours, said belief never wavered in the CD camp.
"We just stayed composed as we went on to get a win but we probably shouldn't have got ourselves in that position," said the 27-year-old Whanganui representative player who frustrated the defending champions' bowlers with Black Caps batsman George Worker's brisk 53 runs from 66 balls, including nine boundaries on a fast outfield.
CD captain William Young, the top T20 run scorer, also played a pivotal role in anchoring the innings with 57 from 51 balls.
The Stags had a great start with the ball, removing the top order cheaply although opener Chad Bowes, coming off a century in the previous round, made a defiant 43 runs.
Michael Pollard, Henry Nicholls, Tom Latham came and left for parking meter change before Todd Astle stopped the rot with 62 runs at No 5.
Captain Andy Ellis, batting at No 7, was 93 not out from 103 balls and No 8 Jamieson showed allround ability with 67 runs from 43 balls, including eight boundaries and a lusty six.
Smith said CD kept their aggressive bowling stance on a good pitch and felt the the Kings' total was a par score.
Christian Leopard made his List A debut with a cameo 26 runs from 13 balls, including four boundaries and a six.
"It's a little too hot for cricket," said a laughing Smith, who felt T20 wasn't his format after he was dropped although he had hurt his hand and hadn't played early this summer.
They play the Otago Volts in round six in Invercargill on Sunday although parts of South island are bracing themselves for a heatwave as well.