Pauline Astier walked to the line in overtime Sunday with the game hanging there and made both free throws with 19.3 seconds left, then later sank two more as the New York Liberty beat the Washington Mystics 98-93. For a player in only her second WNBA game, it was the kind of finish that turns a short-term fill-in into a real storyline.

Astier has been with New York for about two weeks and was stepping in for the injured Sabrina Ionescu, but she played like someone who had been in the system much longer. She finished with 18 points on 60 percent shooting, seven assists, five rebounds and two steals in nearly 35 minutes, then helped close out the overtime win at the foul line.

She said she was just trying to breathe when the pressure came, and then told herself, “OK, it’s just more free throws.” The approach fit the rest of her night. After a debut in Friday’s win over the Connecticut Sun, Astier has produced 11 assists with only two turnovers across her first two WNBA games, showing the kind of steady ballhandling the Liberty needed with Ionescu out.

Jonquel Jones said Astier kept the offense moving by splitting double-teams and playing with comfort down the stretch. “She plays with a lot of confidence and a lot of maturity,” Jones said, adding that she is “super excited to see her just continue to mature and grow in this league and get even more comfortable.” Astier, for her part, said she does not feel much pressure and is simply trying to enjoy being with the team while still chasing a high goal as a competitor.

The performance put Astier in rare rookie company. She was only the third rookie to post a stat line like the one she produced Sunday, joining Paige Bueckers and Candace Parker. Both of those players went on to win Rookie of the Year, a benchmark that adds a little more weight to a two-week stay that has already looked far more settled than temporary.

Jones said Astier was “out there splitting double-teams and stuff,” then joked, “Girl, you gonna make my hair fall out. Just hold the ball.” But the veteran also made the larger point: Astier was comfortable, did what needed to be done and helped deliver the win. That is what made Sunday matter for New York. The Liberty did not just survive without one of their top guards. They found a rookie who handled overtime, the pressure and the late possessions like she belonged there.