New York, Sept. 1 -- Defending champion Carlos Alcaraz said Novak Djokovic's shock first-round exit at the US Open was surprising but insisted he is focused on taking his title defence one match at a time, according to the ATP Website.

Djokovic suffered a five-set defeat to Mariano Navone in a marathon battle that lasted over four hours, marking his first opening-round loss at a Grand Slam since the 2006 Australian Open.

The 24-time Grand Slam champion was drawn in Alcaraz's half of the draw, meaning the Spaniard could have faced Djokovic in the semi-finals. However, Djokovic's early exit has now opened up Alcaraz's path in the tournament.

Speaking after his straight-sets win over Roman Safiullin, Alcaraz admitted he was surprised to s...