NEW YORK: On the American Labour Day holiday, US Open defending champion Carlos Alcaraz went to work and eased past Italian Matteo Arnaldi 6-3 6-3 6-4 on Monday to reach the quarter-finals.Through the first week of the season's final Grand Slam, the world number one has been putting in routine shifts and dropped only one set en route to the last eight.But the second week is the business end of a Grand Slam when the draw has thinned out and serious contenders surface.In Alcaraz's rear view mirror are relative unknowns, like Arnaldi and Dominik Koepfer, but further ahead lurk familiar danger men such as Russians Daniil Medvedev and Andrey Rublev.He will next face either Italian sixth seed Sinner or 12th seeded German Alexander Zverev.Alcaraz has not shown his best yet on the New York hardcourts but like a hot Wall Street stock the Spaniard is trending in the right direction.There have been a few hiccups and lapses but the 20-year-old's raw talent, power and repertoire of weapons make him the man to beat and he is on track for another showdown with arch rival Novak Djokovic.Under a closed roof on Arthur Ashe Stadium, Alcaraz was solid from the start against a man who was playing in the Flushing Meadows main draw for the first time.It took a few games for Alcaraz to size up his opponent but once the Spaniard did it was pretty much one way traffic.Alcaraz took charge with a break for a 4-2 lead in the first set and then broke again at the start of the second to find himself 2-0 up.The feisty Italian had his moment in the third set, breaking Alcaraz at 2-1, but the Spaniard immediately broke back and then broke again to seal victory.Later Arnaldi confirmed what most already knew - he could see no holes in Alcaraz's game."(I)