Nalbandian, the blond-haired world number eight, won 6-2, 6-2, 4-6, 6-4 in two hours 39 minutes to record his fifth win over Davydenko in their seven head-to-head meetings.

With Russia taking a 2-1 lead after Saturday's doubles rubber, the 24-year-old Nalbandian had no choice but to step up to the plate and deliver to keep his country in contention.

He started confidently, breaking his rival's serve early for a 4-1 lead in the first set.

Davydenko, currently ranked third in the world, fought back but was ultimately undone by a series of unforced errors, allowing Nalbandian to break again in the eighth game to earn a one-set lead after 34 minutes.

The second set was a carbon copy of the first. Nalbandian broke again in the fourth and eighth games to take a commanding lead.

The big serves in the third set did not make an appearance until the ninth game, when Davydenko broke Nalbandian's serve to win the set in 42 minutes.

Davydenko traded breaks with his Argentinian rival throughout the fourth set but Nalbandian's accuracy paid off and he claimed victory when the 25-year-old Russian sent a backhand into the net.

On Friday Davydenko had given the hosts the advantage by beating Juan Ignacio Chela 6-1, 6-2, 5-7, 6-4 in the opening rubber, while Nalbandian beat Russia's Marat Safin in straight sets to level proceedings at 1-1.

Russian duo Safin and Dmitry Tursunov lifted their side 2-1 up by beating Nalbandian and and Agustin Calleri in straight sets 6-2, 6-3, 6-4 in the doubles clash on Saturday.

Safin and Chela will decide the tie in the last singles clash later on Sunday.