Daily Bagel: American men, Serena, Wozniacki cruise through in Madrid

The U.S. men went 3–0 in Madrid on Monday as John Isner, Sam Querrey and Steve Johnson grabbed wins, remembering Elena Baltacha one year later and more interesting reporting, writing and quipping from around the Internet.

The Daily Bagel is your dose of the interesting reporting, writing and quipping from around the Internet.

• Serena Williams hasn't had any problems with her tough draw so far. She lost just one game to Madison Brengle in the first round and on Monday she lost just four to Sloane Stephens, winning 6–4, 6–0. She'll face either Victoria Azarenka or AjlaTomljanovic in the third round. 

• The U.S. men went 3–0 in Madrid on Monday. John Isner beat Adrian Mannarino 7–6(2), 6–4, Sam Querrey beat Thanasi Kokkinakis 6–4, 6–7(6), 6–3 and Steve Johnson beat Alejandro Gonzalez 4–6, 6–4, 7–6(4). Johnson's reward? A second round match against Rafael Nadal. 

• Caroline Wozniacki has also cruised through the draw. She's already dropped two bagel sets in her first two matches, with a  7–5, 6–0 win over Christina McHale in the second round. She'll face Agnieszka Radwanska in the third round. 

• Andrea Petkovic was forced to withdraw from the Madrid Open due to gastrointestinal illness. It doesn't sound pleasant:

[tweet=https://twitter.com/andreapetkovic/status/595287450643202048]

• Sam Stosur has looked surprisingly sharp through two rounds after she beat Angelique Kerber over the weekend and Kaia Kanepi on Monday. She faces another quality veteran, Svetlana Kuznetsova, in the third round. Kuzentsova opened her tournament with a win over No. 8 Ekaterina Makarova and then beat Garbine Muguruza 6–3, 5–7, 7–5 in the second round on Monday. 

• It's been a year since Elena Baltacha died from liver cancer. You can still give to the Elena Baltacha Foundation here. 

• Andy Murray's face when he realizes he's been asked to change his shorts on court after winning the Munich Open is priceless:

[youtube=https://www.youtube.com/watch?v=2Um1v-EfSyg]

• This is pure magic from Roger Federer in the Istanbul final:

• Pretty remarkable numbers for Frances Tiafoe, who will make his Grand Slam debut at the French Open:

In 6 weeks @FTiafoe improved from 816 to 293 #Emirates #ATP Rankings & at 17y, 3m youngest American in Top 300 since Michael Chang in 1989.

— Greg Sharko (@SharkoTennis) May 4, 2015

• And in honor of today, we leave you with this:

[tweet=https://twitter.com/SI_Tennis/status/595322119338070016]