US Open: Possible pitfalls in Serena Williams' path to history

Top-ranked Serena Williams has some tricky challenges in her quarter of the US Open draw made Thursday, but the three-time defending champion remains a runaway favorite to make more tennis history.

The 34-year-old American, who completed a "Serena Slam" of four major wins in a row by capturing Wimbledon last month, is trying to complete the first calendar-year Grand Slam since Steffi Graf in 1988 and match Graf`s Open Era career record of 22 major titles.

Russia`s third-ranked Maria Sharapova, who has lost 18 of 20 against Williams including 17 in a row, is a possible semi-final foe.

Second-ranked Romanian Simona Halep, who pushed Williams to three sets in last week`s Cincinnati final, and Danish fourth seed Caroline Wozniacki, whose 10 losses in 11 matches with Williams include last year`s US Open final, are the champ`s highest-ranked possible finalist foes.

"Right now I`m looking forward to just playing tennis," Williams said. "That`s all I want to do."

Williams could face elder sister Venus, a seven-time Grand Slam champion, in the quarter-finals of a draw section that features nine Americans, many of whom idolize Serena.

"It`s better than in the round of 16. That`s how I look at it," Serena Williams said of a potential sibling showdown.

"I don`t look at the draw. I didn`t see the `American quarter.`"

Serena is 15-11 in tour-level matches against Venus, having won their most recent meeting in the fourth round at Wimbledon. 

They have split four career US Open matches, Serena taking the most recent in a 2008 quarter-final.

But also lurking as a possible quarter-final rival this year is Swiss teen Belinda Bencic, who defeated Serena in a Toronto semi-final earlier this month.

"She really reads the ball well and she really fought really well," Williams said of Bencic after the loss in Canada. "She never gives up and she fights hard."

Serena will open against Russia`s 86th-ranked Vitalia Diatchenko, whom she has never played, and could face a second-round date with Croatian Mirjana Lucic-Baroni, against whom she is 2-0.

However, they last faced each other in the second round at Wimbledon in 1998.

Sloane Stephens, who won her first WTA title earlier this month at Washington, is a possible third-round opponent and she has one upset win in their six meetings at the 2013 Australian Open quarter-finals. 

Williams avenged the loss in the fourth round of the 2013 US Open and has beaten Stephens three times this year, although it took rallying from first set losses in the round of 16 at the French Open and Indian Wells.

Poland`s 15th-ranked Agnieszka Radwanska, 0-8 against Williams including a 2012 Wimbledon final defeat, is a possible round of 16 roadblock in Serena`s history run.