NEW YORK (AP) -- Venus Williams got her Grand Slam groove back just in time.
Way down Wednesday night, Williams turned her game on when she needed to, then got some help from a fading foe and beat No. 3-seeded Jelena Jankovic 4-6, 6-1, 7-6 (4) to return to the U.S. Open semifinals for the first time since 2002.
Williams was able to do what her sister, Serena, couldn't in the quarterfinals the night before: overcome a daunting deficit against a top opponent. And now Venus will play the woman who beat Serena, No. 1 Justine Henin.
"I was so disappointed. I watched. More than anything, she's my little sister, so watching her be upset is hard for me," Venus Williams said. "I've got to play well Friday for her."
In the other semifinal, 2004 Open champion Svetlana Kuznetsova will meet No. 6 Anna Chakvetadze, a matchup between two Russians.
Against Jankovic, the older Williams took a while to find the mark, falling behind by a set and a break. But by the end she was playing as well as she did en route to winning Wimbledon in July for her sixth Grand Slam title.
Jankovic made four unforced errors to allow Williams to take control in the tiebreaker. And the American ended it with a swinging forehand volley, an appropriate conclusion given that she made 55 trips to the net, winning 39 of those points. Jankovic was far less aggressive, pushing forward only six times.
Williams dictated play in general, finishing with a whopping 60-17 edge in winners.
"First of all, I want to say, 'Well done,' to Venus," Jankovic said. "She deserved to win. She was better at the end."
Part of the problem for Williams at the outset was Jankovic, of course.
Jankovic enjoyed nearly every moment out there, grinning while waiting to receive serves and laughing even when she shanked a ball off her ankle or, later, when she slipped to the ground and did a full splits on a key third-set point.
Williams, meanwhile, was straight-faced throughout. Until, that is, the match was won. Then, she allowed herself a smile.
Jankovic broke in the very first game, managing to return serves of 115 mph and 119 mph, and capping it with a perfectly placed lob. That was the first of four lob winners that Jankovic curled like a rainbow over the 6-foot-1 Williams, including one that was so good it drew applause from the American's mom.
Jankovic broke again for a 4-1 edge by smacking a return winner off a 100 mph serve. Then, serving for the opening set at 5-4, Jankovic fell behind love-30 and easily could have folded, much as she did when she blew a huge lead against Henin in last year's Open semifinals.
But this time, she hung tough, taking four points in a row -- including ending one 19-stroke exchange with a backhand winner -- to grab the set. That drew loud chants of "Yell-eh-na!" from Serb supporters standing at the top of the upper deck.
The second set started with more of the same. Williams hit two double-faults -- she wound up with eight -- and wildly missed a swinging volley several feet long to set up another break point. Jankovic converted it with -- what else? -- a lob, then held up a fist and smiled at her mother, who smiled right back.
And right there is where Williams flipped a switch, her game suddenly as bright as all of the flash bulbs popping around Arthur Ashe Stadium. She took seven of the next eight points, opening a six-game sweep through the end of the set.