Mayweather KOs Ortiz in fourth round

Boxing: Floyd Mayweather Jr. remained unbeaten Saturday night by knocking out Victor Ortiz with a right hand late in the fourth round in Las Vegas.

The punch came just after the two fighters had hugged in the middle of the ring after a head butt by Ortiz clearly irritated Mayweather. As they separated, Mayweather shot out a right hand that put Ortiz on the canvas, and he was counted out as he struggled to get up.

“We touched gloves and we were back to fighting and then I threw the left and right hand after the break,” Mayweather said. “In the ring you have to protect yourself at all times.”

It was a wild end to a fight that Mayweather was dominating until Ortiz seemed to intentionally head butt him in the corner. After referee Joe Cortez took away a point and separated them, the two met in the center of the ring to resume action. After a brief embrace, Mayweather shot out a left, then a right that put Ortiz down.

It was the 42nd straight win for Mayweather as a pro.

• Morales wins piece of fourth world title: Mexican boxing great Erik Morales won a piece of a fourth title, stopping late replacement Pablo Cesar Cano in a junior welterweight bout in Las Vegas.

Morales, the last fighter to beat Manny Pacquiao, battered and bloodied Cano before the fight was stopped after the 10th round with blood streaming down the side of Cano’s face from a cut next to his left eye.

Rose takes commanding lead

Golf: Justin Rose pulled away with a 2-under-par 69 to take a four-shot lead in the BMW Championship in Lemont, Ill.

Even as Cog Hill began to play more difficult under mild sunshine, Rose made only one bogey as everyone around him began to fold. He saved par on the final hole with an 8-foot putt to stay well clear of John Senden of Australia.

Mark Wilson started the third round tied for the lead but had a 77.

Geoff Ogilvy gave himself a good shot at two cups – the FedEx Cup and the Presidents Cup – with four birdies on the back nine for a 68 that left him five shots behind. He was tied for third with Bill Haas, who made a double bogey on the 16th but still shot 69.

• Allen up a stroke: Michael Allen shot a 4-under 68 to open a one-stroke lead over fellow Americans John Cook and Jay Don Blake after two rounds of the Songdo IBD Championship in Incheon, South Korea.

Cook and Blake shot 5-under 67s and are 9-under 135 heading into today’s final round at Jack Nicklaus Golf Club Korea. Mark O’Meara (69) and David Peoples (70), a co-leader after the first round, were a stroke back at 8-under.

• Teenager builds lead: Teenager Lexi Thompson shot a 5-under 67 in the Navistar LPGA Classic in Prattville, Ala., and is in position to become the youngest player to win an LPGA tournament.

Thompson, who turned 16 in February, is at 15-under 201 and has a five-stroke lead heading into the final round at the Robert Trent Jones Trail’s Capitol Hill complex. Paula Creamer set the age record for a multiple-round tournament when she won in 2005 when she was 18.

Wendy Ward of Edwall, Wash., shot a 72 and is well off the pace.

Raiders’ Janikowski charged with assault

NFL: Oakland Raiders kicker Sebastian Janikowski was charged with assaulting a woman a year ago in Walnut Creek, Calif., the Contra Costa Times reported.

According to court records obtained by the newspaper, the woman said the 33-year-old player used force against her on Sept. 24, 2010, but she did not report what happened at the time. The paper said Janikowski was charged with misdemeanor battery and false imprisonment.

“This incident occurred over a year ago, Sebastian was not arrested, we were aware of this matter and this is not news,” Raiders CEO Amy Trask said in a statement.

The charges carry a maximum sentence of 18 months and a $3,000 fine.

On Monday night, Janikowski tied an NFL record with a 63-yard field goal in Oakland’s opener.

Dixon captures pole for Indy Japan

Auto racing: New Zealand’s Scott Dixon secured pole position for today’s Indy Japan at Twin Ring Motegi in Motegi, the last IndyCar series race to be held in Japan.

Dixon posted the best lap of 1 minute, 38.3918 seconds to edge Will Power of Australia by 0.0276 seconds. American driver Graham Rahal was third.

Danica Patrick, who had her only IndyCar win here in 2008, will start 23rd in her final IndyCar series road event. Patrick will make a full-time move to NASCAR next season.

U.S. women earn draw with Canada

Miscellany: Abby Wambach converted an early penalty kick and the U.S. drew 1-1 with Canada in Kansas City, Kan., in the Americans’ first match since losing the World Cup final to Japan.

Melissa Tancredi scored just before halftime for Canada, which ended a seven-match losing streak to the U.S..

• Hall of Famer Gavitt dies: Dave Gavitt, one of basketball’s most influential leaders the last 30 years, has died. He was 73.

He died in a hospital near his hometown of Rumford, R.I., after a long illness.

Gavitt was a member of the Naismith Memorial Hall of Fame and the first commissioner of the Big East Conference. He led Providence to the Final Four in 1973.

• Serbia, France trail in Davis Cup semifinals: Serbia and France won doubles matches against Argentina and Spain, respectively, to stay alive in the Davis Cup semis after being swept in the opening singles.