Great Britain's Amir Khan is fighting Brooklyn's Zab Judah in a junior welterweight title unification bout on Saturday at the Mandalay Bay Resort & Casino in Las Vegas (10 p.m. ET/7 p.m. PT, HBO).

Khan -- currently No. 14 in SI.com's pound-for-pound ratings -- is the reigning WBA champion at 140 pounds, while Judah holds the IBF belt. (Timothy Bradley holds the WBC and WBO titles.)

The classic matchup between youth and experience is one of the summer's most anticipated bouts.

Enormously popular in Britain since capturing Olympic silver in Sydney at 17, Khan won his first 18 pro fights at lightweight before suffering a shocking 54-second knockout loss to 15-to-1 underdog Breidis Prescott. Humbled, he linked up with Freddie Roach and resurrected himself at junior welterweight, outpointing Andreas Kotelnik for the WBA 140-pound championship in July 2009 and becoming the third-youngest Briton to win a world title. He's since made four defenses, including a unanimous-decision victory over hard-hitting Marcos Maidana in December 2010 that was named Fight of the Year by SI.com and the Boxing Writers Association of America.

Judah had already won five major title belts -- two at 140 pounds and three at 147 -- by the time Khan turned pro in 2005. He's been in against some of the sport's finest talents, including Kostya Tszyu, Floyd Mayweather Jr., Cory Spinks and Miguel Cotto, but he'd become known for his erratic behavior as much as his ability, suffering mystifying mental lapses in his biggest fights. Now 33, the born-again Christian is desperate to prove his best days aren't behind him, and he's shown a more mature outlook while making one last run at the top with recent Hall of Fame inductee Pernell Whitaker in his corner.

When Khan's proposed unifying bout with WBC and WBO light welterweight champion Timothy Bradley fell through, the Briton agreed to fight Judah after the two waged a war of words on Twitter. (The split heavily favors Khan, with Judah making 45 percent of the U.S. revenue and none of the British money despite bringing a title to the table.) Yes, Judah is a heavy underdog, having not beaten a world class fighter since edging Cory Spinks for the undisputed welterweight title in 2005 -- but he's the most talented opponent Khan has ever fought.

Both Khan and Judah are boxer-punchers with extraordinary reflexes who blend speed and power to explosive effect. Khan is the superior combination puncher, while Judah packs better one-punch power.

Most believe Judah's best chance is to land a flush shot on Khan's chin, though Khan did much to dispel questions about his ability to take a punch in December's victory over the hard-hitting Maidana. At 5-foot-10, Khan is tall for a junior welterweight and will try to keep Judah at a distance, which means Judah will depend on head movement and foot speed to work his way inside and test his opponent's jaw.

Each comes in with flaws the other could exploit: Khan sometimes neglects to tuck his chin, while Judah drops his hands -- a habit that led to a knockdown early in his last fight with Kaiser Mabuza.

Both fighters benefit from a wealth of boxing knowledge. Khan works under Roach, a four-time Trainer of the Year, which means sparring sessions with Manny Pacquiao. Judah's recent partnership with Pernell Whitaker, a defensive genius during his fighting days, has yielded promising rewards thus far -- though Whitaker has yet to establish himself as a successful trainer.

Oddsmaker William Hill lists Judah as a 4-to-1 underdog, while Khan is a 1-6 favorite.

A tough one to call. Judah is as live an underdog as you'll see, and the Brooklynite's hand speed, southpaw stance and veteran savvy will test Khan early. If the Mabuza fight is any indicator, Judah's defense is dramatically improved under Whitaker. But once Khan begins to find range with that crisp jab and starts to put rounds in the bank, Judah's frustration will mount and he'll make mistakes. Khan's stamina and work rate will carry him as the fight moves into the middle and late rounds, and he'll make it to the finish line with a healthy points lead despite a few scary moments. Khan by unanimous decision.

Join the conversation about Khan-Judah on Twitter. Track the hashtag #KhanJudah to see who's tweeting what about Saturday's fight.

· @AmirKingKhan (Amir Khan)

· @SUPERJUDAH (Zab Judah)

· @hboboxing (HBO Boxing)

· @ChrisMannixSI (SI.com's Chris Mannix)

· @BryanAGraham (SI.com's Bryan Armen Graham)

· @timdalhberg (Tim Dahlberg, Associated Press boxing columnist)

· @GarethBOXUFC (Gareth A. Davies, Daily Telegraph boxing columnist)

· @NYPost_Willis (George Willis, New York Post boxing columnist)

· @latimespugmire (Lance Pugmire, Los Angeles Times boxing columnist)

· @kieranmulvaney (Kieran Mulvaney, Reuters and ESPN boxing columnist)

· @GoldenBoyBoxing (Khan's promoter)

· @Main_Events (Judah's promoter)

· @mandalaybay_LV (Mandalay Bay Hotel & Casino)

· HBO's Jim Lampley, Max Kellerman, Emanuel Steward and Harold Lederman will be ringside for the main event and undercard.

· The referee assigned to the main event is Tony Weeks, a Nevada referee whose prominent fights include Khan-Maidana, Hopkins-Jones II, Mayweather-Marquez, Pacquiao-De La Hoya and Pavlik-Taylor II.

· The fight will be replayed Sunday at 10 a.m. ET (HBO) and 4:30 p.m. ET (HBO2), Monday at 1 a.m. ET (HBO) and Tuesday at 11 p.m. ET (HBO2).

· On the undercard: Peter Quillin vs. Jason LeHoullier, 10 rounds, middleweights; Gary Russell Jr. vs. Eric Estrada, 8 rounds, featherweights; James Kirkland vs. Alexis Hloros, 8 rounds, middleweights.

MANNIX: Judah puts tumultuous past behind him for one last shot at top

P4P: SI.com's latest pound-for-pound ratings

Looking ahead to Khan-Judah | Khan's Greatest Hits | Judah's Greatest Hits