There was some fear that the second half of the boxing calendar would be a dud, but that all changed last week when Gennady Golovkin and Kell Brook signed off on a bout in September at O2 Arena in London. The two boxers are not just two elite middleweights, but also among the best pound-for-pound fighters in the world. 

While most boxing fans were pleading for a Canelo Alvarez to fight Golovkin in 2016, this might be the next best thing for Golovkin, a knockout specialist who has dominated his division. Brook, meanwhile, will be fighting in front of his home fans.

After Golovkin and Brook settle their differences, another great fight between two of boxing's best stars should follow. Light heavyweight Sergey Kovalev, who successfully held off challenger Isaac Chilemba on Monday, will meet Andre Ward in November, should Ward win his August fight against Alexander Brand. Both Kovalev and Ward are top pound-for-pound boxers.

But where do Golovkin and Brook stand in our latest rankings? How about Ward and Kovalev?

Here's our top 10:

No. 10 - Guillermo Rigondeaux (16-0), super bantamweight

A defensive specialist, Rigondeaux has built a strong following after winning two gold medals, and defeating all 16 of his professional opponents. The Cuban would be higher on this list if he had more fights to his credit, but that should change once his visa issues get sorted out.

No. 9 - Kell Brook (36-0), middleweight

A strong showing against middleweight Golovkin will quickly move him up the rankings. Brook is a smart boxer who knows how to pick his punches, but he is a major underdog by moving up from welterweight to fight Golovkin. 

No. 8 - Errol Spence (20-0), welterweight

Only 26 years old, and looks light the next great boxer. Spence has won his last six fights by TKO and has barely struggled against any of his opponents. He will have a tough test in Leonard Bundu in August, but expect Spence to continue his dominance. 

No. 7 - Keith Thurman (27-0, 1 NC), welterweight

"One Time" showed his resilience in a tight bout with Shawn Porter in June. Thurman has power and patience, so when he unleashes a good punch it often does damage. He's only 27 years old, but fights like a seasoned veteran.

No. 6 - Terence Crawford (28-0), junior welterweight

Would be higher on this list if he had bouts with better boxers. But the talent is there, and Crawford seems destined to rule the welterweight division. He fights on July 23 against undefeated Viktor Postol.

No. 5 - Sergey Kovalev (30-0-1), light heavyweight

Kovalev is among the best knockout artists in boxing, but needed a decision to hold off Isaac Chilemba in his last fight. He will jump higher on this list if he comes away with a victory over Ward. Kovalev went 12 rounds to defeat Bernard Hopkins in 2014, so he may have trouble against a disciplined boxer like Ward.

No. 4 - Canelo Alvarez (47-1-1), middleweight 

His only loss was to Floyd Mayweather, who defeated everyone he faced. Since the loss, Alvarez has gone on a tear. The hard-punching Mexican defeated James Kirkland in convincing fashion, then held off veteran Miguel Cotto. In his last fight, Alvarez dropped Amir Khan. We're all waiting on him to fight GGG, which should happen in 2017.

No. 3 - Andre Ward (29-0), light heavyweight

Ward is a complete fighter, and has never been truly tested in his career. His defensive skills, combined with his speed and power, are big reasons he is expected to edge Kovalev. How Ward fares against Kovalev will determine is legacy.

No. 2 - Roman Gonzalez (45-0), flyweight

"El Chocolatito" is the total package. A hard puncher in a division that lacks knockout artists, Gonzalez should continue winning in dominant fashion. It will be interesting to see how the 29-year-old does when he moves up in weight. Expect big things to come for the Nicaraguan.

No. 1 - Gennady Golovkin (35-0), middleweight

GGG deserves to be at the top of the list because he not only wins, but wins with so much ease. He has won 22 consecutive fights by way of knockout, and even top contender David Lemieux didn't look like he had much of a chance when he lasted until the eighth round. Golovkin has not proven he can be a defensive boxer because he's so good at knocking out his opponents, but he will face his toughest test when he steps in the ring with Brook.