Great Britain's Davis Cup captain Leon Smith has paid credit to both Andy Murray and Juan Martin del Potro after their marathon opening rubber in the Davis Cup semi-finals.

In a match lasting five hours and seven minutes, Del Potro finally prevailed in five sets to give Argentina a 1-0 advantage in Glasgow, and Smith has acknowledged the difficulty that both players faced in putting on a match of such quality.

Smith told BBC Sport: "Credit to Andy and Juan for a match of high quality between two of the best players in the world right now.

"It's the same for everyone, particularly Andy and Juan who win lots of matches and go deep into tournaments, but playing the Davis Cup at this time of year, a stage of the season where a lot of tennis has been played already, is difficult."

Later on Friday evening, Guido Pella overturned a set deficit to beat Kyle Edmund in four sets to move the South Americans one win away from a place in the final.