Serbia advanced to semi-final of Davis Cup after Djokovic's triumph

World No. 1 and Australian Open champion Novak Djokovic's victory over Sam Querrey of the United States on Sunday advanced Serbia into the semi-finals of the Davis Cup.

Djokovic, who had to battle through an ankle injury he suffered in the opening set, earned a 7-5, 6-7 (4/7), 6-1, 6-0 win to give the Serbians an insurmountable 3-1 lead in the best-of-five tie against the Americans.

It is the second win for Serbia in four years over the 32-time titlist USA. In their only other previous Davis Cup encounter Serbia defeated the Americans in Belgrade in 2010.

"I am happy I managed to play the whole match," Djokovic said. "I played really well in the third and fourth set.

"I am sorry for team USA but it was a thrilling weekend for all of us."

Djokovic had to play through the pain of a bad ankle which he sprained in the third game of the opening set.

"I took some anti-inflammatories and they kicked in at the end of the second set. The anti-inflammatories were very strong," he said.

Djokovic said he probably wouldn't have finished the match if it wasn't a Davis Cup competition.

"I hope I didn't make it worse," he said. "If I wasn't playing for Serbia and didn't have my team watching me I don't know if I would have continued."

The 25-year-old Djokovic clinched the victory over world number 20 Querrey with a backhand winner, ending the two hour, 35 minute match.

Djokovic blasted 12 aces, hammered 41 winners and won 75 percent of his first serve points.

Querrey had seven aces, eight double faults and made 58 unforced errors, compared to 47 for Djokovic.

Serbia will now meet either Canada or Italy in the semi-finals in September.