In the feature night match on center court the No.5-seeded Jankovic never stopped fighting against Barthel, who got into the draw as a lucky loser, edging the German, 26 76(8) 63. Barthel had all kinds of chances - she was originally up 62 31, she was a game away at 62 65, and she had four match points in the second set tie-break - three at 6-3 and another at 7-6. But Jankovic just kept clawing back.
Other winners on Day 2 were Carla Suárez Navarro, who beat Ekaterina Makarova, 60 64, Roberta Vinci, who beat German qualifier Annika Beck, 63 62, Anastasia Pavlyuchenkova, who out-hit Latvian qualifier Diana Marcinkevica, 63 62, Svetlana Kuznetsova, who beat Italian qualifier Gioia Barbieri, 62 63, and Alisa Kleybanova, who won a hard-hitting match with WTA rising star Ajla Tomljanovic, 62 64.
Kuznetsova has always played well in Stuttgart. Having reached the semifinals three times here on indoor hardcourts in 2004, 2006 and 2007, she won the tournament in its inaugural year on indoor red clay in 2009, beating - among others - Li Na, Elena Dementieva and Dinara Safina en route to the title.
On Tuesday, Kuznetsova dropped just 12 points in eight service games and broke Barbieri four times en route to a 65-minute victory, in what was the Italian's first ever WTA main draw-level match.
"So far, so good," Kuznetsova said. "I'm happy with how I played and happy that I'm in the next round."
Kuznetsova, a two-time Grand Slam champion and former No.2, will have a tough test in that next round - Simona Halep, the WTA's biggest breakthrough star of the last year and the No.2 seed here.
Halep leads Kuznetsova in their head-to-head series, 2-1, and has won their last two meetings.
"The last time we played, in Rome last year, I lost to her very easily," Kuznetsova said. "She's a very good player. She's had an amazing year, and an amazing finish to last year. It's going to be a tough match, but it will be good for me to have this challenge and I hope to play my best against her."
The first round wraps up and the second round will get going in Stuttgart on Wednesday.