BELGRADE, Serbia — The Czech Republic retained the Davis Cup title by beating Serbia 3-2 in the final Sunday after Radek Stepanek swept past Dusan Lajovic in the decisive singles match.

The Czech veteran beat the 117th-ranked Lajovic 6-3, 6-1, 6-1, converting his first match point with a volley. That sent about a thousand visiting Czech fans at Belgrade Arena into wild celebrations, blowing trumpets and beating their drums.

Stepanek spread his hands on the court as Tomas Berdych and other Czech teammates mobbed him.

“This is an amazing moment,” Stepanek said.

The Czechs won their second straight Davis Cup title, with last year’s its first as an independent nation. Serbia won its only crown in 2010, beating France in Belgrade.

Lajovic, who has a 5-12 record on the ATP tour and had never played in the Davis Cup before this weekend, replaced Janko Tipsarevic, who missed the final with a heel injury.

He also lost his first singles against Berdych on Friday — his first career best-of-five-sets match — and was thrust into the biggest match of his life against Stepanek. The 23-year-old Serb started well, breaking Stepanek in the opening game of the match. But the 34-year-old Czech responded swiftly with two consecutive breaks to take a 5-2 lead.

Stepanek then broke Lajovic for 3-1 in the final set and added another before serving out the match.

Serbia captain Bogdan Obradovic said his team’s chances of winning the title were hurt by Tipsarevic’s injury and a 12-month doping ban against Viktor Troicki, who helped Serbia win its only title.

“We couldn’t find the real replacement for the two,” Bogdanovic said. “We’ll try the next year.”

The Czechs got the crucial point in Saturday’s doubles to go up 2-1. Second-ranked Novak Djokovic then kept alive Serbia’s hopes by beating Berdych 6-4, 7-6 (5), 6-2 Sunday to improve his career record against the Czech to 15-2.

“We both entered this match with a lot of tension,” Djokovic said. “I managed to break his resistance in the second set.”

Berdych was leading 5-4 in the second-set tiebreaker when he sent wide an easy backhand volley at the net. He lost a point on his serve, and Djokovic took his first chance to serve out the set.

Djokovic, who improved his winning streak to 24 matches since losing the U.S. Open final against Rafael Nadal in September, converted his first match point with an ace, bringing cheers from the 17,000-strong boisterous Serbian crowd at the arena.

“It’s really hard to find right and correct words to explain at what level he’s playing and how strong Novak is,” Berdych said. “He is now the best player when he’s playing indoors, and that’s what he proved today.”.