<p>Former world number one Ana Ivanovic has been on a rollercoaster ride since reaching the top of the tennis world in 2008 but the 24-year-old Serbian is on the upswing after reaching the US Open quarterfinals on Monday.<br /><br /></p>.<p>“It's amazing,” the 12th-seeded Ivanovic said after a 6-0, 6-4 win over unseeded Bulgarian Tsvetana Pironkova put her into a Grand Slam quarterfinal for the first time in four years. “I have been here in the fourth round quite a few times, so to make that step and reach the quarterfinals, and also the first time since ’08, I'm very thrilled.”<br /><br />Ivanovic, now ranked 13th, will not have much time for celebration since her victory propelled her into a last eight encounter with red-hot Serena Williams.<br /><br />The fourth-seeded Williams, riding high after a London summer that brought the 30-year-old American another Wimbledon title and Olympic gold in women's singles, charged along with a 6-0, 6-0 walloping of Czech Andrea Hlavackova.<br /><br />Ivanovic, who used a potent forehand to register 18 winners against Pironkova, said it was hard to explain her fade after starting the 2008 season with a runner-up showing at the Australian Open followed by triumph at Roland Garros.<br /><br />“Like a rollercoaster,” she said. “There were some good moments and some tough ones, but it's a process. I understand it better now.<br /><br />“You can't have everything at the same time. You have to be consistent on practice courts and then in the matches. I felt I had that this year.”<br /><br />Ivanovic has lost all three previous meetings against Williams, including twice at the US Open. Last year, she fell 6-3, 6-4 to the American in the last 16 at Flushing Meadows. “I put myself lots of times in opportunities for the big matches and the big wins, and I never managed to do that. Now I have another chance, and I really hope I can pull it together this time,” Ivanovic said.<br /><br />Ivanovic said she has gained strength from childhood friend Novak Djokovic, who last year surged to the world number one with triumphs at the Australian Open, Wimbledon and US Open. “We did speak a lot. He obviously had a great year last year. He's a dear friend of mine. It's great to get some experience from someone like him,” said Ivanovic.<br /><br />Ivanovic, who has recovered from a foot injury, also said she relished the chance to play Williams for a spot in the semifinals.<br /></p>
<p>Former world number one Ana Ivanovic has been on a rollercoaster ride since reaching the top of the tennis world in 2008 but the 24-year-old Serbian is on the upswing after reaching the US Open quarterfinals on Monday.<br /><br /></p>.<p>“It's amazing,” the 12th-seeded Ivanovic said after a 6-0, 6-4 win over unseeded Bulgarian Tsvetana Pironkova put her into a Grand Slam quarterfinal for the first time in four years. “I have been here in the fourth round quite a few times, so to make that step and reach the quarterfinals, and also the first time since ’08, I'm very thrilled.”<br /><br />Ivanovic, now ranked 13th, will not have much time for celebration since her victory propelled her into a last eight encounter with red-hot Serena Williams.<br /><br />The fourth-seeded Williams, riding high after a London summer that brought the 30-year-old American another Wimbledon title and Olympic gold in women's singles, charged along with a 6-0, 6-0 walloping of Czech Andrea Hlavackova.<br /><br />Ivanovic, who used a potent forehand to register 18 winners against Pironkova, said it was hard to explain her fade after starting the 2008 season with a runner-up showing at the Australian Open followed by triumph at Roland Garros.<br /><br />“Like a rollercoaster,” she said. “There were some good moments and some tough ones, but it's a process. I understand it better now.<br /><br />“You can't have everything at the same time. You have to be consistent on practice courts and then in the matches. I felt I had that this year.”<br /><br />Ivanovic has lost all three previous meetings against Williams, including twice at the US Open. Last year, she fell 6-3, 6-4 to the American in the last 16 at Flushing Meadows. “I put myself lots of times in opportunities for the big matches and the big wins, and I never managed to do that. Now I have another chance, and I really hope I can pull it together this time,” Ivanovic said.<br /><br />Ivanovic said she has gained strength from childhood friend Novak Djokovic, who last year surged to the world number one with triumphs at the Australian Open, Wimbledon and US Open. “We did speak a lot. He obviously had a great year last year. He's a dear friend of mine. It's great to get some experience from someone like him,” said Ivanovic.<br /><br />Ivanovic, who has recovered from a foot injury, also said she relished the chance to play Williams for a spot in the semifinals.<br /></p>