Magdalena Rybarikova kisses the trophy last summer after winning her second consecutive Citi Open title. (Katherine Frey/The Washington Post)

Early in her first-round match at last year’s Citi Open, Magdalena Rybarikova appeared to be in the midst of an unprecedented stumble, a near meltdown by her Citi Open standards, against American Christina McHale.

The tournament’s defending champion had lost a set on the hard courts at William H.G. FitzGerald Tennis Center, something she hadn’t done in five matches the year before.

“Oof,” the perpetually stoic Rybarikova remembered thinking. “Now it’s going to be tough to defend the title.”

Five wins and one year later, the 25-year-old Slovak enters this week’s Citi Open as the two-time defending champion, unbeaten in 10 Citi Open matches.

Even with a strong 311-209 career record and the world’s No. 37 singles ranking, her perfect record at Rock Creek Park — where she’s won two of her four career WTA titles — is a conspicuous anomaly.

She says the tournament’s “just a good match,” where surface, schedule and weather combine to make her smooth baseline game more formidable in a wide-open field that lacks the game’s biggest names but packs in potential future stars.

The speedy hard courts here play into the 5-foot-11 Rybarikova’s style. “Balls are flying a little more than usual,” she says, “something maybe other players don’t like as much.”

Rybarikova’s solid second serve bounces better, faster and higher in Rock Creek Park.

“Many players have it higher than usual,” she explained. “And also for my slice, when I play that here, it is moving faster. I don’t think the other players like it.”

Washington’s summer humidity bolsters her advantages. Tennis balls travel faster in the heat, so Rybarikova’s groundstrokes close more quickly. That Citi Open schedule-makers avoid playing matches in the heat of the day helps, too. Rybarikova likes to play later in the day, and most Citi Open matches are scheduled for late afternoon rather than late morning.

But for the first time, the relationship between Rybarikova and her favorite tournament may be strained after Friday’s draw.

Eight players were seeded in the 32-player field, leaving the remaining 24, including Rybarikova, to a random draw. Rather than facing a qualifier, wild card or other less formidable first-round opponent, the defending champ drew a first-round match Tuesday with the tournament’s second overall seed, Ekaterina Makarova, the 20th-ranked player in the world.

“Well yeah, it’s a very tough draw,” said Rybarikova, whose laid-back personality and on-court composure helped lift her over a disgruntled Makarova in straight sets in last year’s Citi Open semifinals. “I know she’ll remember last year’s match, so I know it’s going to be tough. But I think it will be tough for her as well.”

Whoever survives that first-round match may eventually encounter fifth-seeded Anastasia Pavlyuchenkova or fourth-seeded American Sloane Stephens, who are both on the same half of the bracket. The tournament’s top overall seed, surprise Wimbledon semifinalist Lucie Safarova of the Czech Republic, looms on the other side of the bracket with rising Romanian Sorana Cirstea .

Regardless of her opponent, Rybarikova hardly ever appears to strain. She is “not really a hysterical girl, but more calm,” as she puts it.

Still, she says she’s disappointed herself in Grand Slams, with her best singles finishes coming when she reached the third round of the 2008 and 2009 U.S. Opens. So she’s trying not to think much about what would be a historic third straight Citi Open title, lest those nerves she hides so well creep back.

“I don’t think there is any player who doesn’t feel the pressure when you have to defend in the tournament. I did it last year, but I will try not to think about it,” Rybarikova said. “For sure it’s going to be very difficult, especially my first round. I’ve got work to do.”