Murray untroubled to progress at US Open

Andy Murray has won nine of the first 10 games to overwhelm Grigor Dimitrov 6-1, 6-2, 6-2 at the US Open.

The comphrensive victory has put Murray into the quarter-finals for the 22nd time in his past 23 grand slam tournaments.

During the changeover right before the last game, it suddenly began to rain, and play was delayed only slightly before the shower passed.

The new retractable roof at Arthur Ashe Stadium was not closed.

The No.2 seed Murray played well, certainly, but he also faced little resistance from No.22 Dimitrov, who accumulated 23 unforced errors and only two winners by the time he trailed 3-0 in the second set.

Murray has won 26 of his past 27 matches, including a title at Wimbledon and a second consecutive singles gold medal at the Olympics.

The 2012 US Open champion will face No.6 seed Kei Nishikori on Wednesday (Thursday AEST).