Report Card: John Isner the new top-ranked American

The Report Card hands out grades for the best and worst from the week in tennis. This week, we focus on the Men's Clay Championship in Houston and WTA stops in Barcelona and Copenhagen.

John Isner improved to 20-7 in reaching the Houston final, surpassing Mardy Fish as the top-ranked American. (Andrew Richardson/Icon SMI)

John Isner: B-plus. By beating Feliciano Lopez in the Houston semifinals, Isner officially relieved Mardy Fish of his duties as the American No. 1, becoming the 12th man to hold the distinction since 1973. He had a chance to punctuate the achievement with his first title of the year but ran into an in-form Juan Monaco in the final, losing out to the Argentine, 6-2, 3-6, 6-3.

But all in all it was a good week for Isner, who definitely wasn't at his best but battled for two comeback wins over Horacio Zeballos (6-7 (3), 6-4, 6-2) and Feliciano Lopez (6-7 (5), 7-6 (4), 6-3) to get to the final. So congrats, Big John. You are officially the No. 1 American, a serious threat on clay, and no longer known simply as that tall guy who played for 32 days at Wimbledon that one time. It was 32 days, right?

Angelique Kerber: A-plus. Remember last September when everyone was left scratching their heads as Angelique Kerber, then ranked No. 92, made one of the more improbable runs to the U.S. Open semifinals? Let's just say the word "fluke" was being bounced around with regularity during that fortnight.

Flash forward six months and Kerber has captured her second title of the year and notched yet another top 10 win, this time beating Caroline Wozniacki 6-4, 6-4, in the Copenhagen final. How good has Kerber been in 2012? Ranked No. 5 in the Race rankings (and only 61 points behind Marion Bartoli for No. 4), Kerber has made the semifinals or better at five of her eight tournaments this year (winning two of them) and she already has four top 10 wins (beating Maria Sharapova, Wozniacki, Li Na and Marion Bartoli). It seems only a matter of time until she breaks into the top 10 and takes over as the top-ranked German.

Juan Monaco: A-plus. Leave it to one of Isner's good buddies to spoil his coronation, but Monaco followed up his semifinal run in Miami with a strong week in Houston to bag his second title of the season. He beat Isner in the final 6-2, 3-6, 6-3, and was the only player to break the American's serve all week. Now up to No. 14, he celebrated the win as all of Houston's past champions have, with a good dip in the pool. Which gave us pictures like these. Everyone wins!

Sara Errani won both doubles and singles titles in Barcelona, the second time she's swept an event's hardware this year. (Getty Images)

Sara Errani: A-plus. For the second time this year, Errani walked away with not only the singles title but the doubles title as well. She did it last month in Acapulco and again this weekend in Barcelona, beating Dominika Cibulkova 6-2, 6-2 in singles and then teaming up with Roberta Vinci to roll over Francesca Schiavone and Flavia Pennetta 6-0, 6-2 in the all-Italian doubles final. Errani dedicated the win to Permario Morosini, an Italian soccer player who collapsed on the field during a game on Saturday.

"This tournament is for him," an emotional Errani told reporters after the final. "It has been very hard. ... It really makes you think. It brings you back to reality and makes you realize many of the things we complain about in life are just pure nonsense. You have to enjoy every minute of life."

Pablo Andujar: A. Didn't I mention after Indian Wells that Pablo Andujar might become a thing? Well the Spaniard successfully defended his only career title in Casablanca, beating Albert Ramos 6-1, 7-6 (5) in the final.

Michael Russell: B-plus. Maybe Tennis Express was on to something when they decided to sign on Russell as a company spokesperson, putting him in some very odd green-screen-type ads. But the Houston resident had a fantastic week at his home tournament, working his way through qualifying (what, no wildcard for the local guy?) to beat Mardy Fish 6-3, 6-1, and Ryan Harrison 6-1, 5-7, 6-3, before losing to eventual champion Monaco. It was fun watching the sleeveless DJ do his thing.

Caroline Wozniacki: C-minus. Wozniacki strolled through much of the week in Copenhagen and entered the final without dropping a set. But her quest to end her eight month title drought (her last win was in New Haven) continues, as Kerber ruined her homecoming and handed the Dane her first loss in three years in Copenhagen.

Jelena Jankovic: C-plus. Jankovic finally stopped her three match losing streak in Copenhagen, beating Laura Robson 6-4, 7-6 (8) in the first round. But her listless 6-2, 6-1 loss to Kerber in the semifinals means she hasn't beaten anyone inside the top 30 since Dubai.

Mardy Fish: C-minus