Tina Charles and Epiphanny Prince each scored 20 points and the Liberty used a stellar defensive effort in the fourth quarter to win its seventh game in a row, topping the Washington Mystics, 74-66, Friday night at Madison Square Garden.

Shavonte Zellous added 18 points and North Babylon’s Bria Hartley had 10 points.

The Liberty (19-12) moved 1 1/2 games in front of Washington (17-13) for the fourth seed in the playoffs.

The Liberty has three games left in the regular season, and the Mystics have four games remaining. The fourth seed earns a bye into the second round.

The win also gave the Liberty the season series advantage and a tiebreaker over the Mystics, having won two of the three games.

The Liberty is on its longest winning streak since 2010 when it won 10 straight.

Hartley’s three-pointer with 1.6 seconds left in the third quarter gave the Liberty a 61-60 lead heading into the fourth quarter. The Liberty then went on an 11-2 run — Hartley scoring five points in the run — to take a 72-62 lead with 1:49 to go. The Liberty limited Washington to just six fourth-quarter points.

advertisement | advertise on newsday

The Liberty had a 43-41 lead at halftime.

Washington’s Elena Delle Donne, who came into the game averaging 18.8 points, had missed the previous six games following thumb surgery. She had six points at halftime, but scored seven in the third quarter as the Mystics cut into the lead. Delle Donne, however, scored just two points in the fourth quarter to finish with 15.

Krystal Thomas led the Mystics with 17 points.

The Liberty is playing its best basketball of the season with wins over the top three teams in the league — the Minnesota Lynx, Los Angeles Sparks and Connecticut Sun — during the winning streak and could catch the Sun for the third seed. The Sun lost to the Chicago Sky, 96-83, on Friday night and have just a one-game lead on the Liberty. The Sky visits Madison Square Garden on Sunday afternoon.