The queen is back. Long live the queen.

Saddled with a doozy of an Australian Open first-round match for being ranked No. 1 and facing questions about her balky right knee, Williams gutted out a 6-4, 7-5 win over Italian Camila Giorgi.

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Giorgi was the top-ranked unseeded player in the year's first Grand Slam, entering the tournament ranked No. 36, according to ausopen.com.

The last time Williams completed a match, she was at the Billie Jean King National Tennis Center in New York, facing another Italian, then-No. 41 Roberta Vinci in the semifinals of the U.S. Open. Serena was two matches away from completing tennis' first calendar Grand Slam since Steffi Graf's in 1988.

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But Vinci shocked Williams in three sets, and the best female player in the world later revealed that her right knee had been ailing for most of the second half of the 2015 season. She wouldn't play another official match the rest of 2015 after the U.S. Open and withdrew from the one match she played in 2016 at the Hopman Cup.

Serena said the knee was no problem against Giorgi at the Australian Open.

"It's great. It was an hour and 43 minutes and I didn't feel it at all," Williams said, according to ausopen.com. "I think I served well today. I got broken once, but other than that, I was able to stay focused on that part. And I was able to serve really well and that really helped me."

Nerves -- the possibility of winning the calendar slam within her reach -- also played a big part of Williams' loss to Vinci. With a clean slate in 2016, Williams had a much easier time with the pressure of the moment.

"I think I was able to stay in it and stay calm today," Williams said on court after the win, according to USA Today Sports. "I'm happy to be back here. Every day to come back out here is just so amazing, it's great. What makes it special for me is that I still get those butterflies and those nerves."

When Serena is on top of her game, she has no rival; thus, if she continues to control her nerves and can keep her knee from flaring up, she has to be the prohibitive favorite win with the title and tie Graf for the most Grand Slams in the Open era with 22.

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