Serena Williams admitted she would have felt disappointed with her season had she not seen off Victoria Azarenka to win the US Open for a fifth time.
At 31, the American is more dominant than she has ever been, and her 7-5 6-7 (6/8) 6-1 victory over Azarenka in New York gave her a ninth title of the year.
She has lost only four matches all season, but two of those have come in grand slams.
When Azarenka recovered from 4-1 down to take the second set with Williams having twice served for the match, it seemed the world number one may have to contemplate more slam disappointment.
But Williams responded superbly and won the third set easily to add the US Open to the French Open title she clinched in June.
She said: "I felt almost disappointed with my year, to be honest. I felt like, yeah, I won the French Open, but I wasn't happy with my performances in the other two slams, and not even making it to the quarter-finals of one.
"So I definitely feel a lot better with at least a second grand slam under my belt this year."
Williams' victory gave her a 17th grand slam singles title, moving her level with Roger Federer.
"It's an honour to be even with Roger," said Williams. "He's been such a great champion throughout the years, and he's just an unbelievable competitor and he's still playing, and he can probably still win more."
There were high hopes the match would be as dramatic as last year's final between the pair, which Williams won after Azarenka had served for the title, and it did not disappoint.
Williams said: "I obviously would have preferred to close it out in straight sets. But going against a great opponent like Victoria, you have to be able to realise that that can happen and you have to keep fighting for everything.
"I thought, 'I have to stay positive'. It was very easy to get down. I didn't want to get down on myself.
"I wanted to be a little strict with myself so I could play better."
Azarenka was in tears at the end but felt there was nothing more she could have done.
The world number two described the determination of both players as rising like boiling water, and she said: "It was a great match.
"There was no letdown. I think in the third set the momentum changed a little bit, and I kind of felt like I lost that momentum.
"But she really made it happen. In that particular moment she was tougher. She was more consistent and she deserved to win.
"I wish I could have done something better. I felt like I had opportunities in the first set as well. But it's okay. I did everything I could.
"The game overall, there are things that could have been better. But I gave my heart. I fought as hard as I could.
"So that's what is important for me, that I lost to a great champion."