Novak Djokovic believes Juan Martin del Potro will be back on the big stage and winning grand slams after falling short in the final of the US Open on Sunday.

Former world number one Djokovic equalled Pete Sampras' haul of 14 slams after outlasting Del Potro 6-3 7-6 (7-4) 6-3 to lift the trophy for a third time in New York.

Injuries have derailed Del Potro's career but the Argentinian was back in a major decider, nine years after claiming the 2009 US Open.

Del Potro was unable to stop the rejuvenated Djokovic, but there was plenty of love in the air afterwards at Flushing Meadows – where both players praised each other.

Serbian sixth seed and Wimbledon champion Djokovic, who also had to get his career back on track following an elbow injury, said during the trophy presentation: "When I had surgery earlier this year, I could truly understand what Juan Martin went through with his surgeries that kept him away from the Tour.

"Difficult times but you learn from adversity. You learn when you're down and things aren't working out as you want them to. I try to take the best part of myself in those moments and thrive on the support of my loved ones to get myself in this position."

Djokovic added: "I would like to congratulate Juan Martin for what he's done in the last four, five years. With his wrist injuries, coming back, still having belief and faith in himself that one day he will be a top player and fighting for grand slams.

"I really wish him all the best. I know that he will be here again with the champions trophy."

Del Potro – the third seed – had earlier lauded Djokovic, telling ESPN: "So happy to play in the final against this magnificent idol. He knows he is one of my friends on Tour and knows he is one player I want to see win titles.

"Of course, I'm sad because I lost but I'm happy for Novak and his team. You deserve to win."

On his own gruelling comeback from injury, Del Potro said: "I never gave up during my wrist problems. I was trying to fix all my injuries to be here once again and I got here after nine years, which is amazing for me because the US Open is my favourite tournament."