Vincent was in great touch but on 10 smashed a Brent Arnell delivery straight at Corey Anderson, and the Bay rep took a smart catch. Next ball a direct hit would have seen opener Mustard stranded but he survived.
The Aces reached 36-1 off 5 overs, with captain Gareth Hopkins settling in to play a superb hand, but the introduction of Anderson brought immediate success when he had Mustard out LBW. Next ball Anderson was nearly in again but the catch off new batsman Anaru Kitchen did not carry to Darren Mitchell at cover.
Anderson underlined what a talent he is by taking a magnificent catch on the long off boundary off Anaru Kitchen, but he was so far away the umpires could not decide what to do without television replays.
In the end Kitchen was given out on the word of Anderson, which is how the game used to be played, but Anderson's good day in the field was about to be shattered. Big-hitting Colin de Grandhomme joined his skipper Hopkins and immediately launched leg spinner Ish Sodhi into the crowd twice.
Anderson made a brilliant diving attempt to catch de Grandhomme off his own bowling but the catch spilt out and worse news came that he had severely damaged his left thumb.
He was unable to bat and hopefully there is no break because he is due to return to South Africa for the one-day series next week. The Black Caps could certainly do with his all-round skills and his fielding in the deep is without peer.
Hopkins brought up his 50 off 41 balls and de Grandhomme continued his batting masterclass in the final over, as he moved to 66 off 30 balls (8 fours and 2 sixes), with the Aces finishing on 180-5. Arnell was the pick of the Knights' bowlers with 2-32.
The Knights got off to a poor start, with the top scorer against Wellington on New Year's Day, Anton Devcich, out early to the first ball bowled by Black Cap Michael Bates.
Marshall hit a four and lofted six before he played a poor shot, leaving the two English imports, Steven Croft and James Foster, as the Knights' best hopes of chasing down a good total as the weather conditions deteriorated.
But the canny Aces bowlers, led by international Kyle Mills with 1-13 off three overs, put the brakes on the Knights' innings as the required run rate rose well over 10 runs per over.
The Knights' 50 took nine overs and the innings needed the same impetus that De Grandhomme injected into the Aces, but it was not to come.
Hopkins missed a stumping chance off Kitchen's bowling, and the ball went for four byes to add to his annoyance, but the Aces were in the ascendancy as the run rate reached 13 per over with nine overs left.
Croft finally got going, with two big sixes flying over long on off Kitchen, as the Knights scored 20 off the 12th over to get back into the reckoning.
The threat of rain in the gloomy light added to the drama, as did the tight off-spin from Bhupinder Singh, who proved difficult to smash to the fence.
Croft struggled for timing and fluency but then played an astonishing stroke for six over backward point as the Knights needed 72 off five overs and then 60 runs off four - the only chance was to start sending cricket balls into the crowd.
Foster did his best with some improvised stroke play but 48 were still needed off the final 18 balls.
Bates had 1-6 off two overs going into the 48th over and he is one of the more difficult bowlers to attack, but in the marginal light that shrouded Bay Oval he was nigh on unplayable. Hopkins took a superb catch to end Foster's brave knock and that was the end of the line for the Knights.