Just when 14,000-plus Argentine fans were wondering whether a 10-year unbeaten home stand was about to come to a shuddering halt by virtue of an improbable Russian comeback, up stepped Juan Martin del Potro, as the next in a long line of young players who have made their mark, for better or worse, in Davis Cup action.

Davis Cup ties rarely prove to be as simple as they seem and that was the case once more this past weekend at the Parque Roca in Buenos Aires. The much-anticipated semi-final clash got off to the expected nip and tuck beginning with Argentina’s No.1, David Nalbandian, against Igor Andreev.

The Russian with a mighty forehand, who happens to be dating compatriot and WTA starlet Maria Kirilenko, had tasted success in South America before with singles wins against Fernando Gonzalez and Nicolas Massu in Chile last year. Once more, Andreev looked like he was more than capable of an upset and putting an end to Nalbandian’s 15-match unbeaten run in Davis Cup competition in Argentina.

After the first set was decided in the Argentine’s favour on a tie-break in which Andreev held an early advantage, Nalbandian went on to record a straight sets win which would have surprised many beforehand. Nalbandian winning in Argentina is, of course, no surprise. Winning without the loss of a set against a clay court opponent as strong as Andreev, perhaps was, and led Argentina to what almost proved to be a fatal mistake the following day.

With Argentina 1-0 up, the pressure was not as great on Del Potro as would certainly have been the case had Russia taken an early advantage. That freedom helped Del Potro produce a crushing display against a disappointing Nikolay Davydenko which resulted in Argentina ending day one perfect and Russian hopes seemingly in tatters. No wins and not even a set to Russia’s name. However, Davis Cup has a way of surprising us when we least expect it.

Argentina captain Alberto Mancini had initially hoped not to need Nalbandian for Saturday’s doubles tie, but the ease of Nalbandian’s win over Andreev enabled Argentina to pair a relatively fresh Nalbandian with Guillermo Canas, while Russia stuck with their original selection of Dmitry Tursunov and Igor Kunitsyn.

In the blink of an eye, Russia were two sets to the good and a crowd that featured many of Argentina’s Davis Cup players of recent years – such as Juan Monaco, Jose Acasuso, Guillermo Coria, Gaston Gaudio and Mariano Zabaleta – were set for a quick disappointment. Or so we thought. Hours later Nalbandian and Canas had levelled up the match at two sets all and even went a break up in the fifth before losing the battle after more than three and a half hours of play.

Russian captain Shamil Tarpischev cheekily remarked that it had been the Russian plan all along to keep Nalbandian on court for as long as possible. It proved to be the best case scenario for Russia while Nalbandian, tired and weary, had to experience the disappointment of having his home unbeaten streak ended and with the prospect of a live fourth rubber awaiting him in less than 24 hours.

If Saturday was disappointing for Nalbandian, Sunday proved to be that and more after Davydenko came from behind to level the tie at 2-2. Having not experienced a Davis Cup defeat at home spanning 16 matches in five years, Nalbandian had now lost twice in the space of 24 hours and all of a sudden Argentina’s hopes of a long awaited home final and first Davis Cup trophy were in danger of being dashed.

Enter Del Potro, the new shining light of Argentine tennis, who was able to step in when Nalbandian – for so long the man who carried the Argentine burden by himself – needed him to produce a tie-defining win. Much like his demolition of Davydenko on Friday, Del Potro hit the floor running, breaking Andreev to start the match and eventually running away with it 6-4, 6-2, 6-1. The victory sparked a volcanic eruption of joy and celebration amongst the crowd, along with the ticker-tape bringing back memories of the 1978 World Cup.

Argentina now face a mouth watering final against Spain in late November on what is likely to be indoor carpet. It’s one of those quirky aspects of sport that Argentina, to date without a Davis Cup title to their name and having always played at home on clay, may end up winning the Davis Cup on home soil the first time a tie in Argentina was not played on clay.