Novak Djokovic's Serbia missed out on the Davis Cup semi-finals as he and partner Viktor Troicki lost the decisive doubles against Russia despite having three match points.

The 16-time Grand Slam champion had levelled the tie by beating Karen Khachanov 6-3 6-3 after Andrey Rublev won 6-1 6-2 against Filip Krajinovic.

But Djokovic and Troicki lost 6-4 4-6 7-6 (10-8) to Khachanov and Rublev in the doubles as Russia took the tie 2-1.

"I let my team down," Troicki said.

At an emotional news conference, the 33-year-old - who sent a straightforward volley long to squander Serbia's final match point - added: "I never experienced such a moment in my career, in my life.

"We were up in the tiebreak. We had chances to finish it - we didn't do it. I messed up in the crucial moments.

"God gave me once to be the hero, maybe to win the Davis Cup in the deciding rubber. Now he took it away. I'm really disappointed with myself.

"At the end there was one point that decided it. And I'm really, really disappointed in myself that I couldn't hold my focus till the end and finish."

Russia face Canada in Saturday's semi-finals.

Great Britain are seeking to join Russia in the last four, with their tie against Germany under way.