Tennis is built on great rivalries, and what could have been the greatest rivalry in women's tennis over the past five years never got off the ground, when in 2008 after Ana Ivanovic and Maria Sharapova crossed paths in the Australian Open final, a close two set win for the Russian in what was nicknamed the 'Glam Slam.' 

The tall blonde became injured a couple of months later and consequently was unable to face off against the svelte Serbian for the rest of that year. At that point, the fascinating rivalry stood 3-2 for Sharapova. Ivanovic would win her sole Major at 2008 Roland Garros while Sharapova sat at home nursing a shoulder injury. 

Sharapova eventually came back after shoulder surgery in the summer of 2009, but by then Ivanovic's level and confidence had fallen well off. Since she raised the big trophy in Paris and briefly held the No. 1 ranking, Ivanovic has amazingly not even managed to reach another Grand Slam quarterfinal. For her part, Sharapova seriously struggled in her comeback but three weeks ago grabbed her fourth Major trophy, the first since her comeback. 

While the 24-year-old Ivanovic and the 25-year-old Sharapova aren’t close personally, she was moved by Maria's triumph. 

"Definitely it's inspiring to see that," said Ivanovic, who will next face No. 2-Victoria Azarenka who beat Jana Cepelova 6-3, 6-3 in the third round.   

"Hard work pays off sooner or later. That's why it's important to keep at it. I think you get what you deserve. I've been working hard.  I've been feeling much better on the court.  I know good things are around the corner.  Seeing her do well and other players getting better and getting their rankings higher up, it definitely inspires me." 

While Ivanovic has taken some less than admirable losses at the majors since 2008, when she has reached the round of 16 she has come up against quality foes -- all of them now Slam winners: Azarenka at 2009 Roland Garros; Venus Williams at 2009 Wimbledon; Kim Clijsters at the 2010 US Open; Serena Williams at the 2011 US Open and Petra Kvitova at the 2012 Aussie Open. 

"I just need one more step. It would be nice," she told me with a laugh. "It's really tough when you look at the draw and say 'Why I am I not over there,' but it's tennis and what comes around goes around. Today I was thinking that I had a really tough third round, but then I thought you have to beat that opponent because no one is going to hand it to you." 

On Friday at Wimbledon, the 14th seeded Ivanovic overcame No. 22 Julia Goerges 3-6, 6-3, 6-4 in a rapid-fire match where rallies averaged three shots. Ivanovic has lost plenty of important three setters at the majors since 2009, but she's been promising that her confidence level has truly been rising over the past year and in the final game, when she was asked to serve the match out, she came up big. Facing a break point, she torched a serve and crushed forehand crosscourt winner. Then she boomed an ace. Then she forced the equally forceful German into a forehand error. 

She is not getting the yips on her serve, backing away from the ball, or simply framing a sitter like she did so often in 2010 and 2011. She bore down, focused and beat a very dangerous opponent. On Court 2, her fans were able to join in her joyous cries of 'Ajde!' rather than muttering with a sigh,  'Oh Ana, not again.' 

"These last few months I have believed and felt I’ve been doing really well," she said. "I have come close and I lost to some good players and felt I had chances. Sometimes I start to doubt and I try to override it by thinking positive because I know I have the game for it. It doesn't come easy, but sometimes you have step up and let it go and accept what happens." 

Ivanovic reached the Wimbledon semifinals in 2007, when she fell to Serena. She hasn't done any real damage in London since then, and most of the reason for that is mental, because when her head has been on straight she has a big enough serve, forehand and good hands at the net to go further. 

Grass forces the deep thinking Ivanovic to be aggressive and not agonize over strategy in long points, so she can play more from instinct. When she was No.1, she played from her gut. 

"If you look at the history of this tournament only aggressive players have won the title, she said. "That what I thought when I was serving for the match, just step up and hit it because if you don't, she will. At least I took charge. This is the game I had in the past. I was really aggressive at striking the ball and I've changed a bit to add a little more spin, but today was not the time to  do that. You don't even have time to think [on grass]. If I were caught up in over-analyzing the match it would be over. I tried to stay in the moment and that's what I'll try to do in my next match." 

Her next match will clearly be a step up against Azarenka, who reached the semifinals at Wimbledon last year and the other day told me how refreshed she feels after a trip home to Belarus following her punch-out at the hands of Dominica Cibulkova in Paris. Azarenka cannot be pleased that she lost her No. 1 ranking to Sharapova, and it must irk her that in just a month's time she's gone from being the belle of the WTA ball to a handmaiden once again.  The Belarusian hasn't dropped a set in three matches and can tear the cover off the ball. 

While Ivanovic and Azarenka are tied at 2-2 in their head to head meetings, the Serbian will be the underdog, as she lost the last time they played in May in Madrid and overall this season, Azarenka has been at a substantially higher level.  

But as Ivanovic says, if you are talented, work hard and have the right intentions, success will eventually happen.  If she can pull off the upset, it might give her faith that she's really back in the elite mix again with the lines of one time rival Sharapova. 

She does feel like she is player to be feared again. It will be interesting to look into the fierce Azarenka eyes on Monday's and see if she is a little bit afraid when she sees Ivanovic across the net clenching her teeth. 

With her chin up, Ivanovic stated: "I’ve worked hard to get into this position to play top players again and she's not going to like to play me either."