Anastasija Sevastova defeated Serena Williams 7-6 (5), 3-6, 7-6 (4) in Fed Cup singles match play on Saturday in Everett, Washington, to even Latvia's best-of-five qualifier-round matchup with the United States at 2-2.
Per Tim Booth of the Associated Press, Williams was previously 14-0 in Fed Cup singles play since 1999, when she first participated in the event.
The United States and Latvia will now have a doubles match to determine who advances. Alison Riske and Bethanie Mattek-Sands will represent the United States, while Jelena Ostapenko and Sevastova will go for Latvia.
Williams and Sevastova engaged in a unique match where eight serves were broken in the first set before the tiebreaker. Williams fell behind 5-2 in that first set but broke Sevastova twice to take a 6-5 lead.
However, Sevastova held her serve when needed most leading into the tiebreak, despite Williams earning three set points. Sevastova won the tiebreaker, 7-5.
Williams didn't encounter much trouble in the second set, winning 6-3 after breaking Sevastova's serve on the first three occasions.
Both players held serve throughout the entirety of the third set. With the tiebreaker tied at four, though, Sevastova won three straight points to take the match.
Sevastova and Williams had met once before, with Williams winning 6-3, 6-0 in the 2018 U.S. Open semifinals.
Williams finishes this Fed Cup round with a 1-1 record after defeating Ostapenko, 7-6 (4), 7-6 (3).
The winner of the USA vs. Latvia doubles match will advance to the Fed Cup Finals from April 14-19 in Budapest, Hungary, with Belarus, Russia, Germany, Spain, Switzerland, Belgium and Slovakia, all of whom have won their qualifiers.