Boxing has recently been dominated by veterans, culminating with last year’s mega-fight between then 38-year-old Floyd Mayweather and a 36-year-old Manny Pacquiao. As they reach the end of their careers, the next generation of stars is quickly climbing the ranks of the sport.

Gennady Golovkin has been the world’s most dominant boxer in the past few years, but his prime might not last much longer as he approaches his 35th birthday. Andre Ward and Sergey Kovalev will meet this November in the biggest fight of 2016, but the two boxers are 32 and 33, respectively.

Some of the best pound-for-pound fighters have yet to turn 30 years old. Here’s how we rank the top 5 boxers under 30:

1) Roman Gonzalez

“Chocolatito” might be the best boxer in the world, regardless of age. At just 29 years old, he’s compiled a 45-0 record, knocking out 38 opponents. After dominating the flyweight division, Gonzalez looks to conquer another weight class, fighting for the super flyweight title against Carlos Cuadras on Sept. 10. He’s expected to win a title in his fourth division, and there might not be anyone that will give him much of a challenge in the near future.

2) Terence Crawford

Terence Crawford, 29-0 (20 KO) Terence Crawford, 29-0 (20 KO) Photo: Getty

Crawford, 28, solidified his position as the second-best fighter under 30 years old when he dominated Viktor Postol on July 23. His unanimous decision victory gave him another light welterweight belt, making him, unquestionably, the king of the 140-pound division. He’ll have a chance to go 30-0 with his next fight, which looked like it might be against Pacquiao. Pacquiao will face Jessie Vargas, instead, and he likely would have been an underdog against Crawford.

3) Canelo Alvarez

Canelo Alvarez, 47-1-1 (33 KO) Canelo Alvarez, 47-1-1 (33 KO) Photo: Getty

It’s hard to believe that Alvarez is just 26 years old and the youngest fighter on this list. He’s also the only one that’s suffered a loss as a pro, but having a defeat at the hands of Mayweather is nothing to be ashamed of. Alvarez is not only boxing’s No.1 draw because of his exciting style, but because he's one of the best at his craft. He’s been able to amass 47 wins, defeating some of the sport's toughest fighters in recent years.

4) Errol Spence

Errol Spence, 21-0 (18 KO) Errol Spence, 21-0 (18 KO) Photo: Getty

Having fought in the Olympics four years ago, Spence doesn’t have the same professional experience as some other fighters on this list. But there’s no questioning his potential, and he continues to show why he’ll be boxing’s next big star. Spence's recent sixth-round knockout of Leonard Bundu marked eight straight stoppages in no later than the eighth-round, and it earned him a future world title fight. Once he gets a win over a champion, Spence will go even higher on the list.

5) Keith Thurman

Keith Thurman, 27-0 (22 KO) Keith Thurman, 27-0 (22 KO) Photo: Getty

With Mayweather retired and Pacquiao seemingly past his prime, there’s an opportunity for a few welterweights to step up as the division’s top fighter. Thurman has the tools to do just that, having gone 27-0 with 22 knockouts. Thurman’s knockout power hasn’t been the same since he started facing tougher competition, but he continues to win convincingly, most recently securing an impressive unanimous decision over Shawn Porter.