NEW YORK (Reuters) - Highlights of the second day at the U.S. Open, the last Grand Slam tournament of the year, at Flushing Meadows on Tuesday (times GMT):

1753 ZVEREV DEFEATS QUERREY IN STRAIGHT SETS

In-form German Alexander Zverev extended his winning streak to 12 matches by completing a routine 6-4 7-5 6-2 win over local favourite Sam Querrey in less than two hours.

1722 OPELKA FIRES 33 ACES, BEATS KWON

American 22nd seed Reilly Opelka, a finalist at the Canadian Open earlier this month, hit 33 aces past South Korea's Soonwoo Kwon to claim a 7-6(3) 6-4 6-4 victory.

Belgian 27th seed David Goffin lost 6-2 7-5 6-3 to American world number 30 Mackenzie McDonald.

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