The women's final of the US Open isn't until tomorrow, but the most anticipated match of the tournament—perhaps of the entire year—is taking place today, when Serena Williams faces Kim Clijsters in the semis. The two have a friendly rivalry, says the New York Times: Both have Open titles, and both made triumphant returns after long hiatuses. Yet while Williams is the world No. 2, Clijsters is unranked; she just came back to tennis after giving birth to a daughter.
Williams has won six of her seven matchups with Clijsters, but the Belgian has torn through the draw, defeating her sister Venus along the way. Both players are going into today's match with guns blazing—not least because the victor can expect an easy final against a younger player tomorrow. "I’m shocked," Williams said of Clijsters' march to the semifinals, in her first appearance at a Slam in 2 years. "It looks like she took a week off." (More Serena Williams stories.)