MELBOURNE (AFP) - Serena Williams will gun for her 10th Grand Slam title and the world number one ranking against Dinara Safina in the Australian Open final after they both came through tough clashes on Thursday. With the roof of the Rod Laver Arena closed as temperatures soared to a sweltering 44.3 C (111.7 F), Williams is hitting form at the right time as she ended Elena Dementieva's 15-match winning streak 6-3, 6-4. The American second seed, who has won the title here three times, threw off the service problems that have dogged her throughout the tournament for a convincing victory to set up a Safina showdown. Third-seeded Safina lost her only Grand Slam final at last year's French Open but looks capable of making the breakthrough after battling past fellow Russian and seventh seed Vera Zvonareva 6-3, 7-6 (7/4). Adding spice to Saturday's decider is the chance to claim the world's top ranking, with the winner dethroning Jelena Jankovic who crashed out in the fourth round. Among the men, Roger Federer goes in search of his 18th Grand Slam final when he takes on old rival Andy Roddick later Thursday while world number one Rafael Nadal is in action on Friday against fellow Spaniard Fernando Verdasco.The odds were against Williams with Dementieva on a hot win streak this year, but the American blasted 10 aces as the Russian's service game fell apart. "It means a lot, I have to go one more and obviously I want to win," said Williams, 28. "I'm excited that I'm playing really consistent, you know, consistently at least making it to the finals of Grand Slams. So that's exciting, too." Williams has not been at her best during the tournament and has admitted she was rusty, which made Thursday's win all the more pleasing."I definitely served better. It's so important to serve well against her because she's a really good returner," she said. "I moved better and I was definitely more consistent and I kept my cool."It was heartbreaking for Dementieva, who was eliminated in a Grand Slam semi-final for the third straight time as her elusive maiden Major title again slipped from her grasp. "Well, I just had a good run, you know, from the beginning of the year," said the 27-year-old, who has now failed to make a Grand Slam final in 41 attempts. "I played a lot of matches, I won all of them. And I feel like today I was not quick enough. I was maybe not aggressive enough against her. "But I have no regrets. I had just a great time here." Meanwhile an incredibly focused Safina was too steady for Zvonareva as she powered to the straight-sets win, giving herself the chance to emulate older brother Marat by winning the Australian Open. "I remember watching my brother on TV winning this tournament, and if I still watched it today I would have tears in my eyes," she said. "It's great that I can follow in his footsteps. He was my idol - he still is my idol - and the fact that I'm doing as well as him is amazing." The chance to claim the number one ranking is another major motivator for the 22-year-old from Moscow."Since I was growing up my dream was to be the number one in the world," Safina added. "To play Serena in the final for the number one is unbelievable." Safina, whose form has fluctuated throughout the tournament, was all business as she took to the court against Zvonareva, taking advantage of a nervous start from her fellow Russian and never looking back.