Maddison Wrixon, 18, tried to fight off a crazed knifeman who tied up Cristian Santana Guerra, 21, then stabbed him to death.
Police said she was expected to pull through.
The alleged attacker, reportedly a friend of the couple, was arrested hours later by police.
Miss Wrixon is thought to have been dating Mr Guerra, from the neighbouring island of Gran Canary, for just two weeks.
The couple were at Mr Guerra's flat in Puerto del Rosario, Fuerteventura's capital, when their friend David, 20, arrived yesterday afternoon.
The friend is alleged to have pulled out a knife, threatened Mr Guerra, tied his hands up and stabbed him repeatedly, puncturing vital organs.
Local reports said Miss Wrixon tried to fight of the attacker, who then stabbed her 13 times, causing her to collapse on the floor.
Her boyfriend ran out of the flat, blood pouring from him, in a bid to get help. Read More