TORONTO – Another Rogers Cup is in the books and its champion for 2016 is Novak Djokovic, who captured his fourth title by defeating Kei Nishikori in straight sets 6-3, 7-5.

For Djokovic, while he did win in straight sets, the title didn't come easy.

For much of this week's tournament, as good as he was, Djokovic was by no means dominant. In particular, his service game wasn't as strong as it usually is, allowing his opponents to be more aggressive. The case was no different at times on Sunday, particularly in the second set.

Despite losing the opening set and falling behind a break in the second, the No. 3-seeded Nishikori won five-straight points to take a 4-3 lead in the set and appeared to have captured the momentum. But Djokovic composed himself and saved his best for this day, roaring back to win the second and deciding set, clinching his first Rogers Cup crown since 2012.

Yet, while Djokovic had struggled with his service game this week, Sunday's championship match was centered on the return game of both players as the No. 1 seed notched five aces to Nishikori's four. Unfortunately for Nishikori, unforced errors played a pivotal role in Sunday's defeat as the Japanese native committed 28 to Djokovic's 18.

Nishikori had his opportunities in the second set but with the world no. 1 serving for the match, he volleyed the ball into the net giving Djokovic the advantage before shanking the Serbian's ensuing serve to give him his seventh title of the ATP season.

On Saturday, Nishikori sacrificed four break points but his resilience made up for it as he defeated Stan Wawrinka in the semi-final. He wasn't so lucky this time as Nishikori's mental errors were costlier, as he struck several shots both into the net as well as high and wide to give Djokovic a 5-2 lead in the opening set, setting the trend for the day.

Djokovic is back on the winner's stage in Toronto, having already reached it in 2007, 2011 and 2012. It was his 30th career Masters 1000 title. But there is no rest for the world's top seed as he will immediately prepare for the upcoming Olympics in Rio where he will look to better his fourth-place finish in London in 2012.

Prior to the single's final, Croatia's Ivan Dodig and Brazil's Marcelo Melo won the 2016 Rogers Cup doubles crown, defeating Jamie Murray and Bruno Soares 6-4, 6-4. Dodig and Melo fired six aces en route to the win and avenge their finals loss from 2014.

Overall, a wonderful week of tennis as Toronto once again played a great host to the Rogers Cup.