What do suppose the chances are that Serena Williams could serve herself to 40-0 leads in three straight games and, when the smoke cleared, still find her opponent serving for the set?

The world No. 1 survived that scenario, not losing the set in question in today's Stanford final. Then she went on to win her fourth tournament of the year, defeating No. 3 seed Angelique Kerber, 7-6 (1), 6-3.

It would take more time and patience than either of us has for me to fully describe the ups and downs of the first set. In truth, it was one of the most ragged displays of tennis at a championship level in recent memory. Both women were painfully inconsistent and unable to close each other out when it most counted, although Williams gradually adjusted to the pace of Kerber’s reliable lefty shots.

After a quick hold and a jump to 0-30 against Kerber’s serve, Williams seemed to lose her timing, while Kerber began enthusiastically slapping her forehand all over to win points. One plus for Kerber was how well she re-directed the ball, the skill most responsible for the way she carved out two breaks to lead, 5-1.

Williams finally played a good game again for 2-5, but in the next game Kerber had a chance to close out the set when she bolted to a 40-15 lead. Williams remained cool, striking a cross-court forehand winner to dispatch the first set point. On the second opportunity, Kerber made a critical unforced error, driving a third-shot forehand into the net to fall back to deuce.

It took Williams three deuces to win the game, but she got the portentous break. She went on to hold, then Kerber utterly collapsed when it was her turn to serve again. She played three poor points to fall behind 0-40, then contributed a double fault. It was now 5-5.

When Williams held for a 6-5 lead, the women had taken turns winning five straight games each. The top seed had a set point in the next game, but made a backhand rally error that ultimately helped Kerber reach a tiebreaker. Williams raced out to a 5-0 lead through a combination of her own excellent serves and Kerber errors. Would Kerber, in keeping with the spirit of the match, now run off five points of her own?

No chance. Kerber won a point for 1-5, after which Williams earned another mini-break and, at set point, rained down an ace.

Once again, that most damaging mistake in tennis—allowing a service break early at the start of a new set—came into play. Williams broke Kerber to start the second set and quickly jumped to a 3-1 lead. Kerber tightened down the nuts and bolts, but the boost Williams got from that early break seemed to embolden her.

The match suddenly took on the order and clarity that was so utterly lacking in the first set. Each woman held for an interval, and in the eighth game Williams got to 40-0 on her serve for, by my count, the seventh time in the match. She belted a cross-court forehand winner to salt that game away, which put a lot of pressure on Kerber’s next service game, at 3-5.

Kerber almost gave away that one, making three errors that gave Williams a 0-40 lead—three match points. Just to add one more improbable touch to this match, Kerber then played three solid points, including a clean winner, to get back to deuce. From there, she made a third-shot backhand error, and Williams converted the ensuing break/match point when Kerber committed the final unforced error of a match that featured over 50 of them.