In a first-round contest between two qualifiers, Carballés Baena recorded his first ATP World Tour win in Casablanca as he defeated David Goffin of Belgium in straight sets. He followed this up with a tightly fought win over João Sousa in the second round. He faced lucky loser Andrey Kuznetsov in the quarterfinals and won in straight sets. His run was stopped in the semifinals by Guillermo García-López, again in a close three-set match. He won his first ATP tournament at the Quito Open in February 2018, beating Albert Ramos Vinolas in the final. This victory resulted in him reaching the highest singles ranking of his career thus far.