After almost a full month away from the WTA Tour, Shahar Pe’er began her clay court season on the right foot on Tuesday afternoon.Pe’er, ranked number 20 in the world, defeated Polona Hercog (52) 6-3, 3-6, 6-1 in the first round of the Porsche Grand Prix in Stuttgart, Germany, hitting an impressive 80 percent of her first serves in.Next up for Pe’er, who will celebrate her 23rd birthday on Saturday, is world No. 8 Agnieszka Radwanska, who ousted 57th-ranked Ana Ivanovic 7-6, 6-4 on Tuesday.Earlier Tuesday, defending champion Svetlana Kuznetsova cruised past Katarina Srebotnik of Slovenia 6-1, 6-2 in the opening round.Kuznetsova won the French Open last year for her second Grand Slam title and is using the Stuttgart event to warm up for the defense of that crown.Meanwhile, Roger Federer’s form dropped drastically as he lost to Ernests Gulbis of Latvia 2-6, 6-1, 7-5 in his opening match at the Rome Masters on Tuesday.It was Federer’s first singles in nearly a month and his first of the clay-court season. The world’s top-ranked player took off several weeks after losing in the fourth round of the Sony Ericsson Open in Key Biscayne on March 30.Federer reached the semifinals in Rome last year and went on to win his first Grand Slam title on clay at the French Open a few weeks later. This year’s tournament at Roland Garros begins on May 23.Federer didn’t face a break point until the fourth game of the second set, when he missed a forehand wide to end a long rally and hand Gulbis a 3-1 lead.Gulbis then broke again to go up 5-1 when Federer made a series of errors – including a rare overhead miss.Federer committed 38 unforced errors to Gulbis’s 39, and trailed 20-33 in winners. Earlier, Novak Djokovic began his bid to reach a third consecutivefinal at the Foro Italico with a quick 6-1, 6-1 win over Frenchopponent Jeremy Chardy.Djokovic won the Rome title in 2008 and lost last year’s final toRafael Nadal. Dudi Sela advanced to the second round of the Challengertournament in Rhodes on Tuesday, beating Alexandros Jakupovic 6-4, 6-3.