NEW YORK (REUTERS) - An out-of-sorts Novak Djokovic scraped his way to a 1-6, 6-3, 6-2, 6-2 win over American wildcard Jenson Brooksby on Monday (Sept 6) to move into the US Open quarter-finals and three wins from tennis immortality.

Chasing a 21st major that would seal a calendar year Grand Slam, Djokovic had difficulty getting into gear against the 99th-ranked Brooksby, who for a moment looked capable of derailing the Serb.