Report Card: Maria Sharapova has clay breakthrough in Stuttgart

Despite admitting clay is her worst surface, Maria Sharapova beat three reigning major champions to win Stuttgart. (Getty Images)

The Report Card hands out grades for the week in tennis. This past week, the ATP stopped at another of RafaelNadal's stomping grounds, and Maria Sharapova broke through on her worst surface.

Maria Sharapova: A-plus. The book on Sharapova all season has been her inability to bring her best when it mattered the most. Going into Sunday's final against Victoria Azarenka, Sharapova had reached the final of three of the four tournaments she had played in 2012 (Australian Open, Indian Wells and Miami) and failed to take a set in any of them. So leave it to Sharapova to come into Stuttgart, a tournament she had never played before, and resoundingly beat a player against whom she had lost badly twice. Oh, and did we mention it was on clay, her worst surface? And in case people were waiting in the wings to throw out the "cupcake draw" defense, well, you're going to have to wait a few weeks. Sharapova beat three reigning Grand Slam champions in three days -- Sam Stosur, Petra Kvitova and Azarenka. In fact, her three-set tussle with Stosur in the quarterfinals and her tightly contested semifinal against Petra Kvitova are two of the best WTA matches we've seen all year.

Rafael Nadal: A-plus. The stats just keep on coming for Nadal, who captured his seventh Barcelona title with a 7-6 (1), 7-5 win over David Ferrer. Nadal became the first man to win two tournaments at least seven times each (he has eight consecutive Monte Carlo titles) and has a chance to claim his seventh French Open title this year. Through two tournaments, Nadal has yet to drop a set on clay this year and he's running a 77-match winning streak in the month of April.

Gilles Simon: A. There's just something about Bucharest that sits well with Simon. It probably helps that most of the top clay-courters are in Barcelona the same week, but that won't matter much to Simon, who took his first title of 2012 without beating anyone in the top 50. The skinny Frenchman has turned his season around nicely in the past month and a half and he's now right outside the top 10 at No. 11.

Kiki Bertens: A. In a week that saw the top four women make the semifinals of a tournament for first time since Wimbledon 2009, Bertens won Fez as a qualifier. So, don't worry, the wacky world of the WTA is still in effect. Bertens jumped up to No. 92 from No. 149 after winning eight matches, including wins over up-and-comer Garbine Muguruza Blanco, Simona Halep and Laura Pous-Tio in the final. Here's how you win your first title with swag: Bertens won her first and last sets of the tournament with a bagel.

David Ferrer: B-plus. You have to feel for Ferrer, who was beaten by Nadal in the Barcelona final for the fourth time, and he also lost to Nadal in the semis in 2007. Then again, Ferrer is like any other clay-courter who would have been dominant on the dirt if not for the presence of Rafa. So, really, when you feel for Ferrer, you feel for the field.

Victoria Azarenka: B-minus. Perhaps the most worrying thing about Azarenka's Stuttgart campaign isn't the fact that she lost her first final of the year, but that she walked away from the tournament with a right-wrist injury. Azarenka isn't one to talk about her injuries so we don't know whether it's just a niggle or a full-blown injury. But in her first tournament since her streak-ending loss to Marion Bartoli in Miami, Azarenka wasn't as convincing. She was getting pushed by Andrea Petkovic before the German went down with an ankle injury trailing 6-2, 4-4, and Mona Barthel also gave her a run, pushing her deep into the third set once again before losing 6-4, 6-7 (3), 7-5. Luckily for Vika, she'll always have Agnieszka Radwanska -- whom she routed 6-1, 6-3 in the semifinals -- as her punching bag. Seriously, can we just chalk up those matches as a bye for Vika? She barely has to break a sweat.

Petra Kvitova: B. Here's the thing about Kvitova: She's not playing poorly. In fact, if you throw out her North American results -- where her playing horribly is par for the course, really -- Kvitova hasn't had any bad losses. But the Czech has yet to make the final of a tournament in 2012. Two of her campaigns have ended at the hands of Sharapova, and in both matches (the semifinals of the Australian Open and Stuttgart), Kvitova has struggled to break Sharapova's serve. When Kvitova plays well, she looks effortlessly unbeatable. But does she have the killer instinct she needs to gut out these tight matches? I'm starting to wonder.

Mona Barthel: A-minus. Any doubts about whether the German would get nervous playing in front of a home crowd were quickly put to rest. The 21-year-old, who only committed to tennis full time last fall after completing her studies, continued her surge. She notched another top-20 win in beating No. 15 Ana Ivanovic and then scored her first career top-10 win in dropping No. 7 Marion Bartoli, both matches in straight sets. Keep an eye on Barthel through the clay and grass swing. Her serve was a revelation last week.

Fabio Fognini: B. Fognini has made a name for himself for a variety of reasons, but one that may always stick is his propensity to just give up in matches. A fighter he is not. In his first tour final of his career, in Bucharest, you'd think Fognini would put the antics aside and battle it out with Simon, himself a bit shaky when it comes to pressure. But once a Fognini, always a Fognini. Simon got the break in the second set and Fognini checked out. A disappointing effort to cap what was otherwise a tremendous week for the Italian journeyman.

Milos Raonic: A. There's absolutely no reason Raonic shouldn't be a factor on clay, and he showed that last week when he finally took down a member of the top four, beating Andy Murray 6-4, 7-6 (3) in Barcelona. Raonic has trained in Barcelona and should be used to the movement on clay. With his tools, he's no less of a threat than John Isner or Juan Martin del Potro should be. I'm looking forward to see whether he can back up these confidence-building wins in Madrid and Rome. If so, we're looking at a French Open spoiler.

Melanie Oudin: A. When I talked to Oudin in early April in Charleston, S.C., she was noticeably cheerful. After years of seeing her walk around the grounds with what seemed like a dark rain cloud following her around, she finally appeared to be in a good place mentally. She parted ways with her old coach, Brian de Villiers, moved her training base to New York and was working hard. Put simply, she was excited about tennis again. That week in Charleston she won back-to-back completed matches for the first time in more than a year. Last week at a $50,000 ITF Challenger in Charlottesville, Va., she won her first title since 2009. How's that for resilience?

Brian Baker: A-plus

So far, so good