Spain conquered the team ranked 119th in the world when defeating Equatorial Guinea 2-1 in a friendly on Saturday night.
Del Bosque, who said on Friday he had agreed to stay on until 2016, fielded a host of reserve players for the match in Malabo but Spain were still comfortably better than their former African colony, ranked 119th in the world.
Defender Jimmy Bermudez levelled with a fine header from a corner in the 36th minute before Juanfran lashed in a loose ball from close range two minutes before halftime.
Spain's victory, their 68th in 83 matches under Del Bosque, was soured by an injury to midfielder Alonso, who was making his first appearance for his country after five months out following surgery on a groin problem and a broken toe.
Alonso, one of several Spain players on the receiving end of some wild tackles from their opponents, many of whom play in Spain's lower leagues, hobbled off and was replaced by Sergio Busquets shortly before the break.