Bastad - Pere Riba has retired after only one game at the Swedish Open on Monday, allowing fifth-seeded Joao Sousa of Portugal to advance to the second round of the clay-court tournament.
The Spaniard won the game before retiring with a neck strain at Bastad Tennis Stadium.
Also in the first round, Italy's Paolo Lorenzi defeated Swedish wild card Markus Eriksson 6-2, 6-1 on his home turf and Dusan Lajovic of Serbia ousted Albert Montanes of Spain 6-3, 1-6, 7-6 (4).
David Ferrer, who won the tournament in 2007 and 2012, is the top-seeded player. He has a first-round bye.