NEW YORK — Jelena Jankovic is finally a Grand Slam finalist.

Overcoming a slow start, Jankovic used fantastic defense and steady groundstrokes to beat Olympic gold medalist Elena Dementieva 6-4, 6-4 Friday in the U.S. Open semifinals.

"As you can see, I have tears in my eyes," Jankovic told the crowd during an on-court interview. "I'm a little bit emotional to be in the final."

Jankovic lost eight of the first nine points and fell behind 2-0 and 4-2. But as Dementieva became more tentative and more erratic, Jankovic reeled off five consecutive games to claim the first set and a 1-0 edge in the second.

Jankovic also trailed by a break at 3-2 in the second set, before coming back again. She got plenty of help — 42 of the 66 points Jankovic won came from unforced errors by the fifth-seeded Dementieva.

The second-seeded Jankovic entered the match with an 0-4 career record in major semifinals, including losses at this year's Australian Open and French Open. But she kept tracking down balls, running along the baseline and stretching her racket, extending points until Dementieva missed.

Several times, Jankovic wound up doing the splits at the end of a point.

"Elena is a great champion, a great player, and she was running me down everywhere," Jankovic said. "I tried as hard as I could to get the balls back."

She'll face two-time U.S. Open champion Serena Williams or Dinara Safina in the title match. If it is Jankovic against Williams, the winner will move up to No. 1 in the rankings.

Jankovic and Dementieva — the runner-up at the U.S. Open and French Open in 2004 — are probably the two best women's tennis players without a Grand Slam championship. Both have a history of coming up jittery in the late stages of majors.

They engaged in an entertaining match Friday despite swirling wind that sent the U.S. flag above the scoreboard at one end of Arthur Ashe Stadium rippling loudly and an early afternoon sun that sent the temperature into the 80s.

Back and forth they would hit, swatting powerfully from the baseline, with the shot count often topping 20 on a single point.

That was partly due to good movement by both, but Jankovic in particular. She sometimes would bend over to catch her breath between points, or stop to chat with spectators. When she got to set point in the first with Dementieva serving, Jankovic drew a time violation by chair umpire Lynn Welch for pausing to wipe away sweat with a towel.

The turning point might have come a little earlier, with Dementieva up 4-2 and love-30 on Jankovic's serve. Two more points, and Dementieva would have served for the opening set.

Instead, this is how things went: Dementieva missed three consecutive service returns, and Jankovic then won the game by ending a 21-stroke point with a backhand winner. Appearing rattled, Dementieva began the next game by double-faulting, and eventually was broken when a 67 mph serve put her on the defensive.

By now, Dementieva was looking up at her mom in the stands more frequently. While she broke Jankovic twice in the second set, Dementieva never was able to stay in front.