MELBOURNE—As usual, Li Na saved the best for last today. I’m referring, of course, to her post-match interview, which has become an annual source of hilarity Down Under. She told us that she lost the first set because it “wasn’t hot enough yet,” and that while her husband can’t cook, it’s OK, because he can “buy [dinner] for me.”

Unfortunately, most of what Li did before her comedy routine was much more forgettable—those of us who saw her 1-6, 7-6(2), 6-3 win over Lucie Safarova hope that it can be forgotten, anyway. Li lost the first set 6-1 in 27 minutes, and finished with more unforced errors (18) than points won (14). From returns to forehands to backhands to swing volleys, pretty much everything that came off Li's racquet landed well out.

It was assumed by most of us that this would all change in the second set. The Chinese had beaten the Czech six straight times, and a Slam wouldn’t be a Slam without Li going walkabout for a set or two. Yet potential turning points—two break points saved at 0-1; a break point earned at 1-2; a full-on service break at 2-2—came and went, and Safarova kept her nose in front. Li tried to find her range, and failing that, tried to drag Safarova down to her level, but neither worked today.

What finally did work was letting Safarova serve for the match at 5-3. With her back to the wall, Li began to play her first—perhaps her only—good tennis of the afternoon. She attacked fearlessly, and hit her spots with her forehands and swing volleys. Yet Safarova clung to the lead long enough to reach match point on Li’s serve at 5-6. After a brief rally, Safarova let her favorite shot, her backhand, fly down the line, and watched with a grimace of pain as the ball sailed three inches over the baseline. She was that close to the upset, and the No. 4 seed was that close to a not-so-funny third-round exit from her favorite Grand Slam.

When Li held serve a minute later, there was a sense that the rest of this one was academic. In reality, Safarova’s match point had been a match point for both players at once—she had to win it right there, or she wasn’t going to win it at all. After losing the tiebreaker 7-2, though, Safarova held on gamely into the middle the third. But at 3-4, her forehand found the net, and just like that Li was serving for the match. She began that game inauspiciously, with a warning for coaching, but she finished it with a hold, and a ticket to a fourth-round match against Ekaterina Makarova. Li is 4-0 against the Russian, though three of those matches have gone three sets.

Li won ugly today, as she admitted—“I couldn’t do anything,” she said afterward. She finished with 17 winners and 50 errors. You might say it’s an accomplishment to put up stats like that and still not lose a tennis match. But that’s the last time Li’s going to be able to get away with it at this tournament.