US Open Fast Forward returns with some of Day 5’s most intriguing matches as the women’s third round begins and the men’s second round concludes.

Jamie Hampton vs. Sloane Stephens:  One win away from a rematch with Serena, Sloane hopes to find a level more similar to her second-round match than her first-round match.  After she barely survived Mandy Minella, she romped past the more dangerous Urszula Radwanska under the lights of Arthur Ashe.  The second-ranked American woman now faces the third-ranked American, who has emerged as a real threat only this year.  Hampton has upset elite opponents such as Petra Kvitova, Agnieszka Radwanska, and Caroline Wozniacki over the last few months.  Her hyper-aggressive style should contrast with Sloane’s high-percentage style.

Lleyton Hewitt vs. Juan Martin Del Potro:  The heavy underdog in this encounter, Hewitt has defeated Del Potro twice on grass while losing both of their matches on hard courts.  His crisp return and agile movement have blunted the Tower of Tandil’s power, leading to matches more competitive than one would expect so late in the trajectory of Hewitt’s career.  The Aussie has turned back the clock for much of this summer, including three semifinals.  Del Potro fought through a grueling four-set battle with Guillermo Garcia-Lopez, looking more vulnerable than other contenders.  To avoid another grueling contest, he will need to rely on his main advantage over Hewitt:  a far more explosive first serve. 

Serena Williams vs. Yaroslava Shvedova:  Fans will recall their epic encounter at Wimbledon last year, one of two severe tests that Williams overcame before winning the title.  The athletic Shvedova has struggled with injuries throughout her career, which have prevented her from fulfilling her full potential.  When healthy, she can strike serves and groundstrokes as fiercely as anyone.  An impressive career in doubles, including two major titles, has sharpened her all-court expertise.  But Serena has been utterly lights-out in the first week of every major this year, racking up bagels and breadsticks by the ovenful.

Agnieszka Radwanska vs. Anastasia Pavlyuchenkova:  The former junior No. 1 from Russia won their only previous meeting on hard courts, although it came four years ago before Radwanska’s evolution into a top-five player.  Pavlyuchenkova has struggled with inconsistent results all season despite winning two titles, but she recorded two bagels in the first two rounds.  The world No. 4 also has advanced smoothly past a pair of Spanish clay specialists as she copes with the death of her grandfather.  Look for Radwanska’s deft all-court game to find the chinks in Pavlyuchenkova’s less versatile baseline armor.

Denis Kudla vs. Tomas Berdych:  This match looks like no contest at all on paper, considering the contrast in the two resumes.  Berdych has embedded himself in the top 10 for years and recently reached the top five, while Kudla has not cracked the top 30.  But the Czech is more vulnerable than most elite players in the first week of majors and to home players at any tournament.  Losses to Gael Monfils in the first round of Roland Garros and to Vasek Pospisil in Montreal illustrate those trends.   If Kudla can stay close, the mentally questionable fifth seed could falter.

Donald Young vs. Florian Mayer:  The most resounding victory of any man at this US Open came most improbably from Young.  A prodigy who appeared to have flamed out years ago, he yielded just two games to an abysmal Martin Klizan.  But Young, who qualified for this year’s main draw, has reached the second week at the US Open before.  Murray awaits the winner in the third round, so their forward mobility is limited.  Still, this is a winnable match for Young, and the points that he would gain from claiming it would lead to valuable direct-entry berths in more main draws.

Kaia Kanepi vs. Angelique Kerber:  These two Ks met in a three-setter at Wimbledon this summer, a match that Kerber likely should have won in straight sets.  Once she let match points slip away in the third-set tiebreak, the German crumbled.  Kanepi, like Shvedova, has found her progress blunted by extended injury absences, yet she too can trade blows with anyone from the baseline.  Looking to recapture the magic of her semifinal run in New York two years ago, Kerber edged through a tight three-setter against Eugenie Bouchard.  Kanepi endured an arduous battle of her own in the first round, so both have shown tenacity to reach this stage.

Stanislas Wawrinka vs. Ivo Karlovic:  Rallying from two sets down to end James Blake’s career, Karlovic showed the same tenacity that he did in returning from viral mononucleosis this summer. The fast courts in New York would seem to benefit his quick-strike style against the methodical baseline play of Wawrinka, at his best on clay.  On the other hand, the Swiss No. 2 dismantled another fast-court specialist in Radek Stepanek with ease.  And the fatigue of adding three qualifying matches to that five-setter against Blake may have sapped Karlovic’s energies.

Alexandr Dolgopolov vs. Mikhail Youzhny:  All three meetings between these two men have reached a final set, although they have not clashed on an outdoor hard court since 2010.  Dolgopolov, who won that match, showed signs of emerging from a season-long swoon with a  semifinal in Winston-Salem.  His fluid service motion sums up the effortless quality of his game, which can veer from sublime to ridiculous without warning.  A more consistent all-court player, Youzhny also enjoyed a strong summer.  Most of those wins came on clay and grass, though, while his hard-court game has lain more dormant.