Making the leap from scrapping for three rounds and 15 minutes to five rounds and 25 minutes doesn't always go smoothly, even for the most seasoned UFC veterans.
But for the fourth straight time, lightweight champ Benson Henderson illustrated why he's the master at prevailing in five-round scraps. He outlanded Gilbert Melendez en route to a narrow split-decision win at UFC on Fox 7.
In the third defense of his belt, Henderson once again proved that getting the upper hand in a tight 25-minute scrap is predicated on hard work and a proper game plan.
Here are the five men who put in the ungodly hours of physical and mental preparation to become the world's best five-round fighters.
He only fought one five-round match in the WEC, but featherweight champ Jose Aldo has won decisions in three of his four five-round UFC title fights.
Aldo used vicious hand combinations, chopping kicks and stifling takedown defense to outwork Mark Hominick, Kenny Florian and Frankie Edgar in five-round title fights.
But "Junior" put on his most brilliant performance in a five-round battle before ever entering the UFC, when he roughed up former champ Urijah Faber at WEC 48.
Aldo outstruck Faber 138-27, including 77-20 in significant strikes. Junior also brutalized Faber's legs with thunderous kicks from bell to bell and nearly finished the bout several times.
Few fighters can hack it for five rounds against pound-for-pound kingpin Anderson Silva.
"The Spider" tends to end monumental fights before the final bell sounds, like when he masterfully KO'd Vitor Belfort with a front kick and punches at UFC 126 or when he brutally TKO'd Yushin Okami at UFC 134.
However, Silva has proved that he can survive and flourish in desperate scenarios in five-round title fights.
Chael Sonnen took Silva to the brink of defeat at UFC 117 before he got caught in a Hail-Mary triangle armbar late in the fifth round to become The Spider's 12th straight victim in the UFC.
A pair of ACL surgeries have kept Cruz on the shelf since October 2011. But the UFC's first bantamweight champ still holds the belt and will jump back into the fire when he finally recovers.
Cruz gutted out decision wins in five-round championship fights in each of his last four outings. In that span, "The Dominator" handled Joseph Benavidez, Scott Jorgensen, Faber and flyweight champ Demetrious Johnson.
Possessing superior intellect and a work ethic that any champ would envy, the 28-year-old Cruz has plenty of time to employ his tricky style in future five-round title fights.
It's easy to make the argument that Georges St-Pierre is the best five-round fighter in the UFC when you examine his last six bouts.
"GSP" has notched unanimous-decision wins in his last six fights, and he's dominated nearly every fight in the process.
Arguably the most cerebral fighter in the history of the sport, St-Pierre has outsmarted Thiago Alves, Dan Hardy, Josh Koscheck, Jake Shields, Carlos Condit and Nick Diaz in his last six outings.
Until an extremely gifted athlete like St-Pierre comes around and decides to outwork the 31-year-old Canadian, GSP will continue to add to his streak of lopsided decision wins in five-round fights.
Lightweight champ Benson Henderson showed why he's the fifth-ranked pound-for-pound fighter in the world when he outshined Gilbert Melendez at UFC on Fox 7 for his seventh straight win via decision.
In a tactical battle, Henderson used whipping leg kicks and hand combinations in high volume to nip a well-prepared "El Nino."
Henderson last tasted defeat in a five-round war against Anthony Pettis at WEC 53. Since then, "Bendo" has looked unstoppable, winning seven fights in a row by decision including four five-rounders.
The best years are ahead for the 29-year-old former NAIA All-American wrestler, who has a skill set that's strikingly similar to that of future Hall of Famer St-Pierre.