Since exploding on the international sporting stage a decade ago, Maria Sharapova has likened the tennis court to a battlefield — no place for currying favor or making friends.

On the red clay of Roland Garros on Saturday, with a French Open title at stake, Sharapova found herself waging a battle on two fronts.

Across the net was 22-year-old Simona Halep, who compensated for her eight-inch height deficit with indefatigable retrieval skills and profound belief, despite the fact she had never contested a Grand Slam final. And then there was Sharapova’s serve, the only shaky aspect of her relentless attack, which threatened to prove her undoing.

But in the tournament’s first three-set women’s final in 13 years, Sharapova overcame 12 double faults to claim the fifth major title of her career and her second French Open, 6-4, 6-7 (7-5), 6-4.

The 6-foot-2 Russian dropped to her knees upon winning the final eight points of a 3-hour 2-minute match that demanded every weapon in her arsenal, as well as a few tactics that sat poorly with the capacity crowd of 15,000 on Court Philippe Chatrier.

With top-seeded Serena Williams tumbling in the second round, the seventh-seeded Sharapova, 27, dwarfed the remaining field in tournament titles (31), career prize money ($28.2 million) and big-match experience. (Saturday was her ninth Grand Slam final.) And she used that experience to rattle Halep when things looked most bleak, fist-pumping and shouting “C’mon!” after Halep’s unforced errors and repeatedly flirting with time violations for the long pauses between her first and second serves.

Neither that nor Sharapova’s customary high-decibel shrieks endeared the Russian champion to the French crowd, whose loyalties appeared to shift mid-match to the Romanian, cheered on by nearly two dozen family and friends in her guest box.

But these were matters of style rather than substance.

And it was the substance of Sharapova’s play — the power of her forehand, which accounted for 30 of her 46 winners, and the fight within — that determined the outcome.

“This is the toughest Grand Slam final I’ve ever played,” Sharapova told all assembled during her on-court interview.

With the crowd erupting in chants of “Si-mo-na!” “Si-mo-na!” Halep’s eyes welled with tears. But with the swipe of a towel, she regained perspective.

“I have to be happy, to smile, because I did everything on court,” said Halep, who will rise to a career-high No. 3 in the world when the rankings are computed Monday. “It’s really tough to play a first [Grand Slam] final in your career, but it’s also amazing to be there.”

Halep firmly established herself as a Grand Slam champion-in-waiting through her array of tactics and, in particular, her refusal to wilt under Sharapova’s blasts.

Two points from a straight-sets defeat and trailing 5-3 in the second-set tiebreak, Halep won four consecutive points to force a third set.

And after falling in arrears 4-2 in the decisive set, Halep battled back to win the next two games, showing no sign of fatigue on a sunny and humid afternoon that Parisians classified as “a heat wave.”

That’s precisely the point in the match Sharapova showed what sets her apart from other competitors in women’s tennis.

“Just when I thought I was close to winning it, I had lost four points in a row,” Sharapova recounted. “Then the match becomes equal. Then you find yourself in a position where you feel like you’re starting over, which is quite difficult.”

As is her custom, Sharapova turned her back to the court at that critical moment, 4-4 in the third, to refocus.

“I just took a moment to reflect and try to think of the things that I was doing to hurt her and the things that were giving me an advantage,” Sharapova explained.

After spinning around, the Russian didn’t lose another point, breaking the Romanian at love and then unleashing four successive blasts to win it.

“Maria’s mental toughness is unmatched,” said seven-time French Open champion Chris Evert, who was asked to present the women’s trophies 40 years after winning her first. “She is ‘in the moment’ better than anyone. She has the shortest memory of bad points.”

The victory also attested to the staying power of Sharapova’s career.

She was just 17 when she dethroned Williams to win Wimbledon, her first major title, in 2004. She ascended to No. 1 in the world in August 2005. But the losses that invariably followed were difficult to bear.

After undergoing shoulder surgery in 2008, she tumbled to No. 126. And the road back to regaining her form and confidence was arduous. But it was in getting back to work on the practice court, Sharapova said, that she found her true happiness.

She threw herself into addressing her weaknesses — chiefly, her serve, which remains a work in progress, and her fitness and movement, which had been liabilities in protracted clay-court matches.

“I treat my career and my work as a very serious profession,” Sharapova explained. “What has got me my success is the fact that I’m a big competitor and that I don’t want to give anyone a chance.”