Ana defeated world No.6 Angelique Kerber 7-5, 7-5 - her first victory over a top 10 ranked player this year - but Serbia lost its World Group I Play-Off tie 3-2 against Germany.
Ana made a slow start and was behind 3-1, 15-40 on serve, but she hit back to level at 3-3 and then she gradually took control of the match, stepping into the court to dominate points wherever possible.
The world No.17 maintained her fine form in the second set and it was the home player who showed greater nerves, as Ana broke to clinch an impressive victory.
Playing her first clay court match in 10 months, Ana defeated world No.28 Mona Barthel 7-6(5), 2-6, 6-2 in the opening rubber of the Germany versus Serbia Fed Cup World Group I Play-Off tie.
Serbian No.2 Bojana Jovanovski then lost 7-5, 6-2 to world No.6 Angelique Kerber, as day one ended all square.
The draw for the Porsche Tennis Grand Prix in Stuttgart has been made. Ana will take on German wild card Andrea Petkovic in round one.
Petkovic is currently ranked 128th in the world. She is rebuilding her career following a horrific series of injuries that came not long after she had established herself in the top 10.
Ana counts the 25-year-old among her friends and has played doubles with her. The pair have met four times before, with the head-to-head series locked at 2-2.
Ana is leading Serbia in its World Group I Play-off against Germany in Stuttgart this weekend. The match will be played on indoor clay at the Porsche-Arena.
Ana is accompanied in the Serbian team by world No.44 Bojana Jovanovski, Vesna Dolonc (99) and Aleksandra Krunic (155).
The German team consists of world No.6 Angelique Kerber, 28th ranked Mona Barthel, Sabine Lisicki (47) and Anna-Lena Groenefeld (178).
The tie represents the first ever meeting between the two nations.
Ana has named her top five European cities to visit on a short break.
The list is visible to members of Club Ana, which is free to join.
The April competition is now online. The prize is an adidas item signed by Ana.
The winner of the March competition is Dimitris Synodinos from Greece.
He correctly answered "0" to the question, "How many Grand Slams has Ana missed through injury/illness since making her slam debut in January 2005?"
Congratulations to him, he wins a Yonex racket signed by Ana.
The April competition will be launched shortly.
Ana's ranking is unchanged at 17 in the latest WTA Rankings, which are published today.
In the Race to the WTA Championships Ana is placed 24th.
Current WTA top 20:
1 Serena Williams (USA) 11,115pts
2 Maria Sharapova (Rus) 10,240pts
3 Victoria Azarenka (Blr) 9,325pts
4 Agnieszka Radwanska (Pol) 6,845pts
5 Na Li (Chn) 5,880pts
6 Angelique Kerber (Ger) 5,500pts
7 Sara Errani (Ita) 5,405pts
8 Petra Kvitova (Cze) 5,225pts
Ana is pictured here wearing the dress that she will debut at Roland Garros in May
Ana was unable to reproduce her recent form and was toppled in three sets by defending champion Timea Babos in the second round of the Monterrey Open.
Babos defied her ranking of 123 with some heavy serves that immediately put Ana on the back foot. It was clear very early on that Ana was going to have her work cut out, in contrast to just 24 hours previously when she triumphed 6-0, 6-0.
