STOCKHOLM (AP) American Jack Sock and Marcos Baghdatis of Cyprus advanced to the second round of the Stockholm Open with hard-fought wins on Tuesday, while Finland's Jarkko Nieminen ended his singles career with a defeat against Nicolas Almagro.

Seventh-seeded Sock hit 11 aces to beat Pablo Carreno Busta of Spain 6-3, 6-7 (1), 6-3 for a second-round match against Fernando Verdasco of Spain.

The 2009 champion Baghdatis was taken to a first-set tiebreaker before beating Sam Querrey of the United States 7-6 (2), 6-1 in a match lasting 77 minutes. He now faces fourth-seeded Bernard Tomic of Australia.

Lucky loser Almagro beat Nieminen, making his 16th straight appearance in Stockholm, 3-6, 7-6 (6), 6-4.

The 34-year-old Nieminen was playing his last ATP event but he is still in the doubles with Johan Brunstrom.

Also, eighth-seeded Gilles Muller of Luxembourg saved eight of 10 break points and hit 16 aces in a 6-3, 6-7 (2), 6-1 win over qualifier Mischa Zverev of Germany.

Steve Darcis of Belgium defeated Adrian Mannarino of France 7-6 (4), 6-4.