Several months ago, many might have assumed they were witnessing the twilight of the legendary career of Serena Williams. However, the American rectified her season by winning the U. S. Open title along with an emphatic, successful climax to the year in the WTA Finals championship on Sunday. With her big surge to the 2014 finish line, Williams now appears far from slowing down.

The veteran triumphantly finished her 2014 campaign by capturing the WTA Finals title in Singapore for the third year in a row and fifth time in her career. But it appeared this result was far from preordained leading up to the tournament. In fact, her status was in question due to a knee injury which forced a withdrawal from the China Open at the beginning of the month.

Exacerbating her unstable position, Williams suffered one of the worst defeats of her career at the hands of Simona Halep as play commenced in Singapore. In just her second match after returning from injury, the American fell to the Romanian by a decisive 6-0 6-2 result. Ironically, Halep could have ultimately eliminated Williams had she fallen in straight sets to Ana Ivanovic later in the tournament. Instead, she gave Williams life by winning a set and was forced to meet her once more. And in an outcome that has been felt by other opponents who had embarrassed Williams, Halep felt the wrath of her retribution in the final, 6-3 6-0.

However, Williams did not garner similar success earlier in the season. The 33-year-old struggled in the first three Grand Slams, with her best result being a round-of-16 loss to Ivanovic at the Australian Open. Elsewhere, she was stunned in the round of 64 at Roland Garros by Garbine Muguruza 6-2 6-2, followed by another early exit to Alize Cornet at Wimbledon. These results induced conversation as to whether Williams had seen her best days.

Further testing the California native, she began to experience illness that forced her out of the Wimbledon doubles and the Wuhan Open. And with a back injury keeping her out of the Qatar Open early in the season, coupled with her recent knee injury, she faced her share of obstacles throughout the season.

Nonetheless, despite her misfortunes, Williams put together a strong run at Flushing Meadows in the season’s last Grand Slam. There, she did not drop a set during the fortnight, earning the title by defeating Caroline Wozniacki in the final. The effort salvaged her Grand Slam season, since despite winning seven titles this year, the barometer of the 18-time major champion is success on the largest stages.

With her collection of Grand Slam titles, one might ponder what fuels the American's fire as she advances to her mid-thirties. Clearly, Williams thrives off of the adversity of a defeat, particularly one in which her performance was subpar. As Sloane Stephens felt in 2013 after she defeated Williams in Melbourne, the ensuing meeting generally finds the intensity spiked. That season, the elder American evened the score with a merciless 6-4 6-1 victory at the U. S. Open.

In 2014, Ivanovic and Halep met a similar fate. After the Serb defeated Williams at the Australian Open, she would fall in their next four meetings. Likewise, Williams played with an edge, appearing to send a message to Halep in the WTA Finals Championship after falling to her earlier in the week.

However, she still has challenges in that regard. She will have to wait until 2015 to avenge three losses in 2014 to nemesis Alize Cornet and an embarrassing defeat to Muguruza at the French Open. Regardless, Williams typically finds another gear when facing opponents who have overwhelmed her in victory.

Additionally, it is clear that she now feels her place in history as well. As accolades continue to compile, commentary on the historical significance accompanies her words more frequently. In 2014, Williams equaled legends Chris Evert and Martina Navratilova with 18 career Grand Slam singles titles. With an additional title, she will even Helen Wills Moody at 19. She still has work to do to equal Steffi Graf's 22 titles, as well as Margaret Court who leads the list at 24. However, if healthy, she certainly is capable of a run for the top.

Nevertheless, after a strong finish to 2014, Williams will enter next year still holding world No. 1 and will be a favorite at the Australian Open in January. With a couple months to heal any lingering ailments, expect a fast start to the season. Her performances at the U. S. Open and WTA Finals may have reintroduced the swagger back to her game. Whereas earlier it appeared there may be chinks in her armor, late in the season Williams proved that she is more than adept at complete domination of an event. Those eyeing their shot at the top will have to earn that position, for Williams does not quite appear ready to yield it just yet.