A bloodied Angel Manfredy earned a hard-fought split-decision victory over the previously undefeated Julio Diaz in an important lightweight bout Saturday in Corpus Christi, Texas.

Manfredy overcame the greater-volume punching of the youngster with constant pressure and by landing the harder, cleaner shots to earn the win.

With the win, Manfredy improved to 39-5-1 (29) and earned his fourth shot at a world title in his up-and-down 12-year career. The entertaining 12-round bout determined the No. 1 position in the International Boxing Federation's lightweight rankings, making Manfredy, who turns 27 next month, the mandatory challenger for IBF 135-pound title-holder Paul Spadafora.

While judge Ruben Garcia saw the HBO-televised bout for Diaz with a 114-112 tally, judges Mark Nelson and Bill Clancy scored it for Manfredy, 115-112 and 114-112, respectively. MaxBoxing.com scored the bout a draw, 113-113.

The 21-year-old Diaz fell to 23-1 (17), suffering his first loss in part because of repeated low blows that caused him point deductions in rounds four and nine. Without the deductions, the bout would have been ruled a majority draw on the official scorecards.

Generally regarded as last year's brightest prospect, Diaz showed poise and patience beyond his age and experience in his first bout to go 12 rounds. The Southern Californian exhibited good legwork, a non-stop jab and classy combinations off the stick, such as a jab-left uppercut-right cross-left hook to the body mixture.

However, although he averaged more than 100 punches per round, many of his straight punches were blocked or nullified by Manfredy's high guard. Diaz, in turn, rolled with many of Manfredy's straight blows to his head.

Neither fighter possessed the power to seriously hurt the other. But while Diaz was busier (he landed 293 of 1,306 total punches -- 22 percent -- according to CompuBox stats), Manfredy was more economical with his power shots (he landed 194 of 997 --19 percent).

Diaz countered Manfredy's rushes well in the first round, although he hit low twice. Manfredy was able to drop a crisp left hook over Diaz's lackadaisical guard. In the second round, Diaz got his jab going, landing to Manfredy's body and face. Manfredy stepped up the pressure behind a sharp jab of his own, but he absorbed a few hard three-punch combinations from Diaz in the process.