Some battles are bigger than others.
Russia's Alisa Kleybanova proved that on Monday at the US Open after a two-and-a-half year absence from the majors because of cancer.
Diagnosed after the 2011 Australian Open with Hodgkin's lymphoma, a form of blood cancer, the 24-year-old marked her return to the Grand Slam stage with a tenacious three-set victory over Puerto Rico's Monica Puig.
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"I just wanted to come back on the court so much," Kleybanova said after her 6-4, 3-6, 7-5 win. "I wanted to play tennis again so much that it (recovering) wasn't a question for me. I saw a tennis court a few months ahead of me.
"I was ready to go through anything. I wanted to be healthy and playing again, and I think that gave me a lot of power."
Kleybanova endured chemotherapy through most of 2011.
Having turned professional at the age of 14, she had reached 20th in the world rankings, won two titles and collected more than $2 million in prize-money.
Now ranked No. 363, she said her determination to regain health was fuelled by the prospect of days like Monday.
"It's tough," she said. "My goal was so big, to get over this. You have to go through this, because you'll get better and things will get better.
"When you have a big goal in front of you, you do everything to reach it. I think for some people, maybe they give up because they don't know what they're going to do.
"Maybe they're insecure. It's like playing a match. You do everything to be a winner."
Kleybanova is reluctant to be viewed as a role model.
"All those things are over for me now," she said.
"I went through them. I came out as a winner in that battle.
"I hear a lot from people that I'm an inspiration for them. A lot of people now look up to me.
"I don't want to be an example. If I am, very nice. But I did this for myself.
"I wanted to play tennis. That helped me to be strong, without giving up or having negative thoughts."
Kleybanova's next opponent will be ninth-seeded Serb Jelena Jankovic.
"Everybody that goes into a match wants to win, feels the tension, feels the pressure," she said.
"The more I play, I'm getting used to it.
"Inside, of course I feel stronger. Everything that you go through, it's always experience.
"It's something negative but also something positive.
"It take it as a lesson. I learn. I tried to look forward and never look backwards, no matter how bad or hard it was.
"Whatever doesn't kill you, makes you stronger."