Italian Simone Bolelli swiftly ended Schwartzman's hopes of success in Bastad, battling back from the brink of losing the opening set to secure a 7-6 (10-8) 6-3 victory.

Schwartzman led 5-2 at one stage in the first, while he also failed to convert two set-point opportunities in the tie-break, as he slipped to defeat in his first outing at the tournament.

Bolelli will next play Henri Laaksonen, who needed just 59 minutes to brush aside the challenge of Matteo Berrettini 6-2 6-2.

Compatriots Pablo Carreno Busta and Fernando Verdasco will meet in an all-Spanish quarter-final after posting wins over Thiago Monteiro and Pedro Sousa respectively.

Meanwhile, at the Croatia Open Umag, surprise French Open semi-finalist Cecchinato battled back from a set down to beat Jiri Vesely 2-6 7-5 7-5 and reach the last eight.

The Italian finally got over the line on his seventh match point, giving him his 16th win in 28 outings on the ATP Tour this season after two hours and 19 minutes on court.

Cecchinato will meet Laslo Djere next after the latter caused a surprise by knocking out ninth seed Maximilian Marterer.

Albert Ramos-Vinolas was another seed to tumble out on Wednesday, the fifth-ranked Spaniard failing to win a game during a one-sided deciding set against Dusan Lajovic, who will play Guido Pella.