STOCKHOLM (AP) — Marcos Baghdatis of Cyprus upset fourth-seeded Bernard Tomic of Australia 7-6 (7), 6-3 Wednesday to advance to the Stockholm Open quarterfinals.

Baghdatis, who won the tournament in 2009, said he had used his "brain a lot" against Tomic.

"You need to be smart on court and not hurry too much," Baghdatis said. "I think I did it very well."

Baghdatis next plays eighth-seeded Gilles Muller of Luxembourg, who defeated John Millman of Australia 7-5, 6-3.

The 32-year-old Muller fired 14 aces in the 76-minute victory.

Seventh-seeded Jack Sock served 10 aces on his way to the quarterfinals with a 7-6 (5), 6-7 (5), 6-4 win over Spain's Fernando Verdasco. The 23-year-old American is seeking his second career ATP World Tour title after winning at Houston in April.