The former KCCA forward's strike came after Yousri Bouzok had given the hosts a 16th-minute lead.
ALGERIAN CUP ROUND OF 32
Paradou 5 MC El Bayadh 0
Former KCCA forward Allan Okello started life at Paradou by scoring on his debut, as the Algerian Ligue 1 side easily brushed aside MC El Bayadh to advance to the Round of 16 of the Algerian Cup.
Paradou will meet ES Guelma in the next round.
A one-sided five-goal scoreline on Thursday carried Okello's name as one of the five different scorers on the day in a comprehensive victory for Paradou.
It was a bold statement for the Ugandan teenage star, who took off himself the sort of pressure that a new arrival carries to a club.
He came off the bench to apply the finishing gloss on an already impressive scoreline, hitting the target on the death to seal an emphatic 5-0 victory.
Okello's strike came after Yousri Bouzok had given the hosts a 16th-minute lead, although it took them 40 minutes to add a second through Bouabta Tarek.
That second goal burst open the creaking floodgates as Abdelakahar Kadri made it a swift third two minutes later to put Paradou in total command of proceedings at the Omar Hamadi Stadium in the capital Algiers.
Hicham Messiad put the tie further beyond Bayadh with goal number four in the 85th minute, before Okello arrived to wrap up the rout late on.
It was a show of total dominance by the hosts, who will have been delighted to have their new Ugandan forward hit the ground running with a debut goal. And for 19-year-old Okello, who moved to the North African club on a four-year deal last month, such a performance will have lifted his confidence.
By the time of his departure from Lugogo, Okello was the club's topscorer in the Uganda Premier League this season, with six goals in the 10 games he played in the first round of the current campaign.
He was also pivotal in KCCA's winning of the CECAFA Kagame Cup Club competition in Rwanda last year.
Okello enjoyed Premier League and Uganda Cup victories while at KCCA. The left-footed forward's move to Paradou added him to the list of several Ugandans playing in North Africa:
• Khalid Aucho (Misr Lel Makkasa Sporting Club)
• Abdu Lumala (Pyramids)
• Emmanuel Arnold Okwi (Ittihad Alexandria)
• Former Vipers captain Tadeo Lwanga (Tanta Sports Club)
• Derrick Paul Nsibambi (Smouha Sports Club)
• Allan Kyambadde (El Gouna)