Marin Cilic found the extra gear required to see off the battling Federico Delbonis in a five-set thriller to give Croatia a 1-0 lead over Argentina in the Davis Cup final.

Croatia's number one looked to be course for a comfortable opening match as he raced into a two-set lead, but Delbonis showed he was up for the fight.

The world number 41 refused to lie down and battled back to level the match and take it into a deciding set, however that was where his heroics ended.

Spurred on by a raucous home crowd Cilic raised his game to another level and that proved crucial as he completed a 6-3 7-5 3-6 1-6 6-2 victory in over three-and-a-half hours.

Any hope Delbonis had of catching Cilic out early on were quickly dashed as the world number six dominated proceedings, only dropping five points on serve in the opening set.

The second went a similar way as the home favourite found the crucial break in the 11th game, his two-set cushion was not as secure as some may have thought though.

As Cilic's first serve began to falter Delbonis took full advantage and, after saving two break points in the seventh game, he edged ahead before pulling one set back.

Buoyed by taking the third set there was no stopping Delbonis - backed by a vociferous travelling support that included Diego Maradona - as his groundstrokes gave Cilic plenty of problems - the Argentine racing into a 4-0 lead on his way to levelling the match.

The decider should have been a classic but Delbonis' form wavered and that gave Cilic the chance to break twice and give his side the early advantage in the final, the 2014 US Open champion taking his record in Davis Cup rubbers to 10 wins from 12 matches.