Djokovic sends Serbia through
Novak Djokovic played through the pain to push Serbia into the semi-finals of the Davis Cup after they saw off the United States in Idaho.
The Serbians came into the final day with a 2-1 lead and Djokovic sealed their progress by seeing off the big-serving Sam Querrey 7-5 6-7 (7/4) 6-1 6-0 in two hours and 35 minutes.
Despite winning 12 of the final 13 games to overpower his 25-year-old foe, Djokovic was clearly struggling after sustaining an ankle injury in the first set.
Querrey capitalised to level the match on a tie-break, although the Australian Open champion recovered and lost just seven points in the final set.
Serbia will face Canada in the final four in September, after the Canadians saw off Italy 3-1 in Vancouver thanks to a clinching singles victory from Milos Raonic.
The heavy-serving Raonic was pushed to four sets by Andreas Seppi but came out on top 6-4 6-4 3-6 7-5, blasting 35 aces, to convert the overnight 2-1 lead into a team win.
Lukas Rosol defeated Evgeny Korolev to give defending champions Czech Republic a 3-1 victory over Kazakhstan in their last-eight tie in Astana.
Leading 2-1 heading into the reverse singles, Rosol overcame Korolev 7-6 (7/5) 6-7 (7/2) 7-6 (7/5) 6-2 in an edgy encounter to claim the decisive point for the Czechs, who in turn became only the sixth nation to hold the number one slot on the ITF Davis Cup nations ranking.
Spain, who have held the top spot for the last four years, slip down a position to number two.
The Czechs, who have won their last seven Davis Cup ties, will next play four-time finalists Argentina, who edged out France 3-2 in Buenos Aires, with Carlos Berlocq defeating Gilles Simon in the deciding rubber.
Jo-Wilfried Tsonga levelled the tie for France with a thumping 6-3 6-3 6-0 win over Juan Monaco in one hour and 42 minutes.
But Berlocq held his nerve against his higher-ranked opponent to seal victory for Argentina with a 6-4 5-7 6-4 6-4 success.