Belinda Bencic, the top seed at her de facto home tournament in Lugano, Switzerland, lost her opening-round match to 182nd-ranked Antonia Lottner, 7-5, 6-2.

Considering Bencic's fine play this season, which includes a Dubai title run and semifinal showings at Indian Wells and Charleston—the latter on clay, albeit the green shade—this is a real head-scratcher. The world No. 20 led the first set 2-0 but largely crumbled from there; had Lottner not double faulted three times in the penultimate game, it would have been a 6-1 second set. Still, Bencic was unable to hold serve thereafter, and her red-clay season is off to a forgettable start.

All credit to Lottner, who had nothing to lose—unlike Bencic, the crowd favorite. Did Bencic feel the effects of her quick turnaround from Charleston, where she played on Friday? Did she succumb to the pressure of being the top seed—which, as Steve Tignor pointed out, hasn't happened in years? Or was it just a bad day on clay?

We may want to know, but I'm guessing Lottner couldn't care less.