The Lions scored 159 in their innings, and restricted the Dolphins to 152 for eight from 20 overs.
The Dolphins, set 160 for victory, had the heart of their batting lineup taken out by Phangiso, as he picked up the wickets of Morne van Wyk (35), David Miller (0) and Cody Chetty (43) in his four overs.
The result meant the Dolphins finished second on the log, and despite their win, the Lions in last position.
The Dolphins were in trouble early, as Cameron Delport was out in the first over of the innings. Lions bowler Pumelela Matshikwe got the ball to move away outside off and Delport could only find an outside edge to Temba Bavuma at point.
Van Wyk and Chetty then joined forces to score 57 for the second wicket.
The partnership was brought to an end when Van Wyk was bowled by Phangiso for 35.
Miller followed the next ball for a duck. Phangiso induced Miller into a drive, but found a faint edge through to Quinton de Kock behind the wicket.
Wickets continued to fall, and Chetty was out for 43, also bowled Phangiso, in the 14th over leaving the Dolphins 94 for six.
Earlier, De Kock once again led the way for the Lions with 37 runs from 28 balls as the hosts got off to a good start. The Proteas opener, was out bowled in the eighth over. De Kock came down the pitch to Alexander and missed a straight delivery, as the Lions lost their first wicket for 59.
The opening partnership between De Kock and Stephen Cook lasted 47 balls.
Cook departed for 22 at slower than a run a ball, clean-bowled by a stock delivery from offspinner Prenelan Subrayen, as the Lions lost their second wicket with the score on 75 at the halfway stage of their innings.
Rassie van der Dussen (14) was out pulling a ball well outside off, and gave Chetty at mid-on an easy catch off the bowling of Alexander.
Bavuma (41 not out) and the experienced Neil McKenzie (40) helped the Lions post 159 for three in their 20 overs. The pair came together with the score on 82 for three in the 12th over. They ended with an unbroken stand of 77 runs from 49 balls.
The pick of the Dolphins bowlers was Craig Alexander with figures of 2/31 in his four overs.