Iago Aspas has claimed that his close friendship with Alvaro Morata helps the pair thrive while playing together on the field.

Aspas and Morata both scored twice in Spain's 8-0 win over Liechtenstein on Tuesday night, which saw Julen Lopetegui's side move one step closer to booking their spot at the 2018 World Cup.

In addition to scoring twice himself, Aspas set up Morata's second of the night in Vaduz, and the Celta Vigo forward has paid tribute to his close personal relationship with Chelsea's summer signing.

"Me and Alvaro get along really well outside of football and we are friends, so hopefully that helps on the pitch," Aspas told Movistar+. "It is a shame that neither of us scored a hat-trick but the important thing was that we won and played really well."

The result against Liechtenstein has seen Spain stay three points clear of second-place Italy, who recorded a 1-0 win at home to Israel, with just two fixtures left to play in Group G.