Bothered by a bad neck that a trainer massaged twice, Novak Djokovic double-faulted seven times and trailed by a break in each set before avoiding the rash of upsets at the Western & Southern Open by taking the last four games for a 7-6 (2), 6-4 victory over Ricardas Berankis on Monday night.

The No. 1-ranked Djokovic was playing his first ATP match in six months because of the coronavirus pandemic; he pulled out of the doubles event Sunday because of his neck.

“I’m trying to deal with it on a daily basis,” he said. “It’s been like that for the past three or four days.”

Still, Djokovic improved to 19-0 in 2020 as he prepares to seek a sixth title from the past eight Grand Slam tournaments when the U.S. Open begins in a week. That major championship’s site in Flushing Meadows is hosting the Ohio-based Western & Southern Open, too, as part of an unusual doubleheader with no spectators.

Djokovic got by, even though he was wincing and stretching his neck between points, then wound up laying on his back — a medical mask and protective glasses on his face — while having his neck manipulated after the first set.

While the tours were shut down, Djokovic tested positive for COVID-19 in June after a series of no-social-distancing exhibition matches he organized in Serbia and Croatia.

As tennis ramps up — this is the first tournament of the resumption for the men; the women returned earlier this month — there have been a host of surprises.

No. 2 seed Dominic Thiem, a three-time major finalist, wasn’t even competitive in a 6-2, 6-1 loss to Filip Krajinovic, and No. 5 Alexander Zverev hit 11 double-faults — five over his last two service games — while being beaten by Andy Murray 6-3, 3-6, 7-5.

Like Djokovic, Serena Williams and Naomi Osaka emerged with difficult wins, while two-time Wimbledon champ Petra Kvitova, the No. 6 seed, lost Monday. Each of the top two women’s seeds, Karolina Pliskova and Sofia Kenin, were beaten Sunday.

Djokovic now meets American Tennys Sandgren, a 6-7 (4), 6-2, 7-6 (5) winner over No. 15 seed Felix Auger-Aliassime, who accumulated 15 double-faults. Another American, Reilly Opelka, eliminated No. 9 seed Diego Schwartzman 6-3, 7-6 (4).

Her yells of “Come on!” filling a nearly empty stadium, Williams was pushed to the brink in her longest match since 2012 before pulling away with a perfect tiebreaker and edging Arantxa Rus 7-6 (6), 3-6, 7-6 (0).

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“I had a crowd in my head or something,” Williams said with a laugh. “For me, it was like there was a crowd there.”

Rus is a Dutch qualifier ranked No. 72 whose flat, left-handed strokes from the baseline gave Williams some trouble. Williams dropped four games in a row in the second set, then did so again in the third, when she fell behind 6-5.

Rus served for the match there and, at deuce, was two points from victory.