Phiri, who was making his debut in professional cricket, lit up Kingsmead with a spectacular knock of 64 not out off just 32 balls to help the Dolphins to a total of 178-5 after the Tuskers had won the toss and elected to field.
The 26-year-old Phiri, who batted at number 6, came to the crease in the 12th over and slammed five sixes and four fours and was a big part of an unbroken sixth-wicket partnership of 71 in 41 balls with Romashan Pillay (15 not out).
The home team then restricted the visitors to 164-7 in their 20 overs to prevail by 14 runs with Proteas fast bowler Anrich Nortje, a new signing for the Dolphins this season, taking 2-27 in his four overs.
The 31-year-old Nortje was playing in his first competitive match for close to six months having last represented the Kolkata Knight Riders in the Indian Premier League in May.
It was a win in their first game of the tournament for the Dolphins while the Tuskers slipped to their second consecutive defeat.
Warriors knock Titans to the floor at St Georges' Park
Matthew De Villiers struck 74, JP King scored an unbeaten 76 and Matthew Boast took four wickets as the Warriors coasted to an 86-run victory at home against the Titans.
De Villiers and King came together with the hosts in trouble at 27-2 in the sixth over before stitching together a 126-run partnership for the third wicket.
King then accelerated towards the end of the innings with his runs coming off 43 deliveries while Proteas left-arm paceman Marco Jansen took 2-29 in four overs for the Titans as he prepares for the Test series in India.
Boast then ripped through the visitors' batting line-up to finish with figures of 4-23 as the Titans were skittled for 107 all out in 17.1 overs.
It was Warriors first win in the CSA T20 Challenge after their opener was abandoned due to rain while Titans lost after an opening day victory.
Daniel Smith's blistering knock helped Western Province overcome the North-West Dragons in their tournament opener at Newlands, while Boland notched their second consecutive win, edging the DP World Lions at the Wanderers.
Western Province successfully defended their domestic women's T20 title after being crowned champions following a 48-run victory against the Dolphins at Newlands on Sunday.
