Friso Gentsch/AP Images

Roger Federer is no longer cause for alarm, but not quite celebration, either. After his first match on his favorite surface ended in a freak loss to 39-year-old Tommy Haas, the Swiss routed world No. 66 Yuichi Sugita in his first match at the Halle Open, and today faced his first real test in No. 29 Mischa Zverev, a lefty whose serve-and-volley game looks peachy on the grass. Though not the sort of guy who consistently makes deep runs, Zverev’s style is screwy enough to topple top 10 players—Andy Murray at the Australian Open and Kei Nishikori in Geneva—unprepared for his compact, unglamorous groundstrokes and aggressive net game, which can startle you out of your normal rhythms. Zverev is one of the cleanest volleyers on tour and, unlike most of his colleagues, has a real appetite for the net, hurtling ahead at any remote opportunity. Few people are eager to run forward while Roger Federer lines up a routine forehand, but Zverev is one of them, and sometimes this courage pays dividends.

It worked for him all through the first set, which he stretched to a tiebreak. Federer often struggled to get the ball into play on his return games, several of which Zverev won at love. Noticing that the Swiss had planted himself solidly inside the baseline, as he usually does—this season more than ever—Zverev often aimed his serves right at his foe’s body, challenging him to pick a side, jump out of the ball’s trajectory, and line up his return, a tricky little run of footwork. For a while Federer got jammed up and misfired on these, but towards the tail end of the set he started to his spots. In fairness, Zverev’s margin of error is slim: If his serve doesn’t hit his mark, right at the body, then he’s just sent a softball right into Federer’s strike zone, one he barely needs to move to crush. This happened often enough to produce a whole reel of pretty return winners:

With one set in the tank Federer began to loosen up a little bit. While dealing with a opponent glued to the net, he showed some nice patience, rejecting initial passing shot opportunities and instead sending screamers right at Zverev, knowing that he would either miss the insanely difficult volley or spit up an easier ball to be put away.

Federer won 7-6 (5), 6-4, and so far on the grass he looks solid, though a bit below his outrageously high standards. Should he keep winning at Halle, now that his only real challenge, sitting on the other half of the draw, is Alexander Zverev (Mischa’s prodigious little brother), he’ll get three more matches to hit his groove before Wimbledon starts.