DR Congo giants Mazembe finished on 11 points, two more than Hilal of Sudan with Tetouan and Smouha in that order with eight and five points respectively.
As early as the 12th minute, the host were up after Samata toe-poked home a low shot from Yaw Frimpong for the opener.
Mazembe went into the break with a two-goal lead as Zambia captain Kalaba scored the second on 31 minutes with a superb shot from close range.
Samata made it three eight minutes after the break with a shot from his non-favourite left foot before a moment of individual brilliance from substitute Roger Assale saw him extend the lead two minutes from time.
The Tanzanian sealed his hat-trick in stoppage time to headline the biggest win of the Congolese this season in the continental club championship.
In Alexandria, Amr Abousabaa put the hosts Smouha up after 21 minutes before Nasr Ahmed grabbed the vital equalizer on 73 minutes to secure Omdurman-based Hilal a place at the semis.
12.09.2015 15H30 TP Mazembe (DR Congo) 5-0 Moghreb Tetouan (Morocco)
12.09.2015 15H30 Smouha (Egypt) 1-1 El Hilal (Sudan)
11.09.2015 20H30 El Merreikh (Sudan) 1-0 USM Alger (Algeria)
11.09.2015 20H30 ES Setif (Algeria) 2-2 MC Eulma (Algeria)
*All times are in local time