The Titans, chasing an unlikely 444 for victory, resumed on 62 for two and the cancellation of the gritty 53-run third-wicket stand happened six overs into the day when Rory Kleinveldt trapped Graeme van Buuren lbw for 23.
Piedt followed up immediately with the wicket of Qaasim Adams for a duck, but the resistance of Heino Kuhn (69) continued until two overs after the drinks break when seamer Dane Paterson had him caught in the slips by Justin Kemp.
There was obviously more determination in the Titans middle-order than in the first innings, when they lost their last seven wickets for 23 runs, as Mangaliso Mosehle (26) batted for an hour-and-a-half and Shaun von Berg dug in for nearly two hours as he also scored 26.
Roelof van der Merwe was the best of the Titans batsmen on the final day, however, as he scored 51 in 128 minutes of resistance, but it was never going to be enough to avoid a heavy defeat for the visitors.
Piedt produced a top-class display of spin bowling in helpful conditions as he took six for 100 in 34.2 overs, while Kleinveldt chipped in with two for 55 to finish with a nine-wicket haul from the match.
Paterson and fellow seamer Travis Muller each took a wicket as well.
The Cobras’ victory deals a hammer blow to the rest of the teams in the four-day domestic series as it means the defending champions now lead by nearly 17 points with just three rounds remaining.
The Knights are in second place, while the Dolphins have moved into third, managing to overtake the Lions, nearly 11 points behind the Central franchise.
The loss, their fourth in seventh matches this season, has condemned the Titans to the bottom of the log, trailing the Warriors by two points.