Hosts Morocco made a perfect start at the 2018 African Nations Championship with a 4-0 win over neighbours Mauritania in Casablanca.
The Mauritanians battled well at the Stade Mohamed V before conceding four times in the final 30 minutes.
Ayoub el Kaabi scored twice as Ismail el Haddad and Achraf Bencharki also found the net for the tournament favourites.
Morocco's squad, coached by Jamal Sellami, includes 12 players who ply their trade in Casablanca with six each from African champions Wydad and city rivals Raja.
Sellami's team includes Achraf Bencharki, who scored five goals in the 2017 Champions League campaign and who is hoping to impress national team coach Herve Renard before June's World Cup.
The Moroccan team defeated their Cameroonian counterparts 3-1 last Saturday in Casablanca in the build-up to the championship.
The hosts will play the tournament with one eye on winning the trophy and the other on trying to force their way into a mainly-overseas-based senior squad, as the World Cup in Russia looms.
Morocco beat Egypt to qualify from the North Zone, before stepping in to replace Kenya as hosts for the tournament.
Mauritania are coached by Corentin Martins who is also coach of main national team.
They next face Sudan on January 17 before facing Guinea four days later.
Mauritania will be looking for their first ever win at a CHAN after losing all three of their matches at their sole previous appearance in 2014, against Democratic Republic of Congo, Burundi and Gabon.
The 2014 CHAN was previously Mauritania's only appearance at a major football tournament.
Most recently they lost 3-1 to Mali in the opening phase of the 2017 Wafu Nations Cup in Ghana.
They qualified by beating Liberia 2-1 on aggregate and Mali 3-2 on aggregate in West A Zone.