Taylor Townsend vs Camila Osorio — R128 — Cincinnati Open

The second serve settled it. Osorio coughed up seven double faults to one and won just 47 percent behind her second delivery, while the Chicago left-hander — a serve-and-volley throwback in a baseline era — took 23 of 43 second-serve return points and struck nine aces to Osorio's two. The break that mattered came in game 6 of the third for 4-2, after Osorio's own break for 1-2 had briefly stalled Townsend, whose 91-percent first-serve resistance in the opener had by then collapsed to 56 in the second. Osorio saved a match point before it ended, 2 hours and 10 minutes in, and the betting market had seen this coming: 10Bet made Townsend the 60 percent favorite despite the 50-place ranking gap. They had no prior meetings on record.