MONTREAL, Canada -- After a bruising baseline battle with numerous twists and turns, World No.1 Simona Halep of Romania claimed her third title of the year at the Rogers Cup on Sunday, outlasting No.3 seed Sloane Stephens of the United States, 7-6(6), 3-6, 6-4.

"This week, it's been an amazing effort," Halep said during her press conference, following the trophy presentation. "It's brutal, the effort for me. This week it was really tough."

Read more: As it happened: Halep captures 2018 Coupe Rogers crown over Stephens

The rematch of the 2018 Roland Garros final between two of the reigning Grand Slam champions lived up to expectations, as Roland Garros titlist Halep fended off four set points to claim the opening set, before emerging victorious over 2017 US Open champion Stephens in a tense final set after two hours and 41 minutes of play.

"[Stephens] makes me play better and better every time we meet each other, that's a great thing for me," said Halep. "Of course, she's a strong player. I think she's a complex, if you say in English, complex player. She has everything."

Both players exhibited a stunning combination of outstanding defense and agile attacking from all sections of the court, and they each won over three-quarters of points on their opponent's second serves. But it was Halep who held on down the stretch, garnering a crucial break for 5-2 in the third and withstanding a fiery fightback by Stephens to get over the finish line on her fourth championship point.

Therefore, Halep claimed the Rogers Cup title for the second time -- she won the event the most recent time it was played in Montreal, in 2016 -- and a third singles title of the season after winning at Shenzhen in January and clinching her maiden Grand Slam title in Paris in June.

"I feel happy," Halep continued. "I feel like, okay, I had a big holiday after French Open, but my game is still there, and also the desire to win, which makes me happy and makes me to relax more. It's not away. I will keep working. I will keep doing the same thing. Hopefully I will have many more."

After a routine hold by Stephens, Halep went on a tear to open the match, cruising through the opening stages due to deep hitting and powerful forehands, many down the line. After breaking Stephens for a 2-1 lead, the World No.1 held for 3-1 from break point down, closing out the game with an ace.

Another impressive game by Halep occurred on the following Stephens service game: a strong forehand forced a netted error by Stephens to bring up break point, which the Romanian converted with a forehand winner down the line. At this point, Halep had picked up four games in a row en route to a 4-1 lead.

But Stephens rediscovered her aggression while the forehand of Halep began to falter. After Halep fired a forehand miscue on a point that would have given her 5-1, the American took one break back for 4-2 with a crosscourt return winner, and leveled the set at 4-4 by swiftly breaking Halep for a second successive time.

The rallies became more grueling as Halep broke Stephens with a crosscourt winner to take a 5-4 lead and serve for the set. But Stephens was unbowed, breaking Halep for a third straight time with a scintillating forehand winner. The American then held two set points on Halep’s serve at 6-5, but a crosscourt backhand saved one, and Stephens netted a return on the second.

They advanced to the tiebreak, where numerous forehand errors by Halep gave Stephens a commanding 4-0 lead, and the Romanian double faulted to put Stephens up 5-1 at the change of ends. But Stephens fired groundstrokes long on both of her service points at 5-2, putting Halep back on serve in the tiebreak.

Another Halep double fault gave Stephens two more set points at 6-4, but Halep saved the first with a stunning crosscourt angled forehand that barely clipped the sideline, and Stephens pushed a forehand into the net to make it 6-6. On the next point, Halep crushed a backhand down the line to hold her first set point, which she converted to claim an intense opening set.

But Stephens was unbothered by the loss of the first set, and after an exchange of breaks to start the second set, the reigning US Open champion claimed a decisive break lead at 2-1 following a Halep double fault while down break point.

The American staved off two break points at 3-2 behind extravagant hitting from her forehand wing, and held for 4-2 at a pivotal juncture. Halep served to stay in the set at 5-3, often deploying a drop shot to generally favorable results as she erased three set points. But Stephens reached a fourth set point, and broke Halep for the set after a backhand by the Romanian went wide.

Halep came out swinging in the decider, using stellar defense to chase down everything Stephens threw at her, and breaking to start the third set. But Stephens rebounded to break back for 2-2 after a scorching forehand winner.

However, Halep claimed a pivotal game when she erased a 40-0 lead for Stephens to break for 3-2 in the following game, as the American fired five consecutive unforced errors. Halep stayed consistent, keeping the rallies long, and raced to a 5-2, double-break lead, as the Stephens miscues mounted.

The No.3 seed put up a valiant effort to stay in the encounter after Halep squandered her first match point at 5-2 with a double fault. The Romanian fired two errors on the next two points to drop serve, and then could not convert either of two championship points on the Stephens serve, the American saving the final chance with a winning volley en route to a hold for 5-4.

Halep, though, would not be denied, using some of her most powerful serving and hitting at the very end of the match, setting up two more championship points after Stephens returned a strong serve wide. Finally, on her fourth match point, Halep slammed her third ace of the match, and fell to her knees in triumph and exhaustion after a grueling fight.

"I really wanted it because I couldn't finish the games before," said Halep. "In the last game I just wanted to hit it, so I was lucky to hit an ace at the match point," the World No.1 said with a smile.