First, Knight showed remarkable skills to collect a bouncing cross-kick, tiptoe the dead-ball line and throw the ball back into play, where Matt Faddes gratefully dove on it for one of the tries of the season.
Later, Knight's effort shone through, out-hustling Manawatu's Heiden Bedwell-Curtis, who had given up on a loose ball which looked sure to go into touch. Knight managed to get his boot to the ball, and won the lengthy race to the line to ensure Otago had a healthy halftime lead.
Unhappy with the first half performance, Manawatu coach Jeremy Cotter made three subs at halftime, including introducing All Blacks first five Aaron Cruden, who received his longest stint on the paddock in several months.
Reported to have a big money offer on the table from Montpellier, Cruden was adept attacking the line and throwing offloads, but Otago proved defiant in defence.
That defence held until the 70th minutes, when Manawatu came storming back into the clash. A try to Jamie Booth was followed by Callum Gibbins crossing the line, but he was adjudged to have been held up as Otago clung on for the victory.
Needing a bonus point win to lock in top spot, Otago fell a try short of the full allotment, meaning Wellington could eclipse them if they collect five points against Waikato tomorrow.
There could be a rematch on the cards next week, with Manawatu requiring results to go their way to book their spot in the playoffs. Currently in third place on 23 points, the Turbos are two points ahead of North Harbour - who are favoured to beat Northland - and five ahead of Bay of Plenty who can leapfrog Manawatu if they beat Hawke's Bay with a bonus point.
Otago 21 (Tony Ensor, Matt Faddes, Adam Knight tries; Scott Eade pen, Fletcher Smith pen)
Manawatu 14 (Ngani Laumape, Jamie Booth tries; Otere Black 2 cons)
HT: 18-7
