Armintie Price had 12 points and Erika DeSouza grabbed 10 rebounds for Atlanta (19-14), which has secured third place in the Eastern Conference. The Dream never trailed and won their fourth straight and seventh in the last eight.
''Tonight was a very good game we played,'' McCoughtry said. ''Kudos to Armintie. ... I think everybody did a good job despite some quarrels. ... The team contributed very well tonight and we just want momentum for the playoffs.''
Carolyn Swords scored 16 points to lead the seventh-year Sky (13-20), who have never made the postseason. Epiphanny Prince added 14, Shay Murphy had 12 and Courtney Vandersloot 10.
Chicago, which has lost three of its last four, remained one game behind fourth-place New York - which lost 78-66 at Tulsa - with one game remaining. The teams split their four regular-season meetings but the Liberty have the second tiebreaker with a better conference record.
''Obviously, it was extremely disappointing with the outcome of the game, more specifically the defensive end of the floor,'' Sky coach Pokey Chatman said. ''That's something we've talked about in several of our last games. You have to keep your man in front of you. At the end of the day, you've got to play from the tip to the horn, especially with some of the limitations we have because of player rotations. We didn't, and therefore we're done.''
With a win Saturday against last-place Washington, Chicago can match its 14-20 mark from last year in Chatman's first season as coach and general manager.
''I think the biggest lesson is trying to help with creating a sense of urgency all the time,'' Chatman said. ''They're pros. They know what's going on. We need to find a way to give the players the confidence to want the ball in their hands.''
Price scored six points while Lindsey Harding added five as Atlanta led 21-13 through one quarter. Chicago pulled within three with 2:28 left in the second, but Atlanta closed with a 7-0 run to take a 41-31 lead at halftime.
The Sky again trimmed the Dream's lead to three points early in the third but the got no closer as Atlanta pushed to a 57-49 advantage by quarter's end. In the fourth, the Dream led by as many as 16 points and Chicago never got closer than nine.
The fifth-year Dream are returning to the playoffs for the fourth straight year, and are coming off two straight trips to the WNBA Finals - where they were swept both times, by Seattle in 2010 and Minnesota last year.
''We're trying to get to 20 (wins) and keep winning,'' Lyttle said. ''It keeps us motivated to go (further). We just need to stay focused and play as hard as we can play because the playoffs is a different scenario.''
Chicago's Olympic center Sylvia Fowles missed her sixth straight game with a calf strain and will miss Saturday's season finale.
The Sky also announced this week that point guard Ticha Penicheiro is retiring. A 15-year veteran, she was named one of the league top 15 players of all time in 2011.
- Atlanta Dream
- Armintie Price
- Angel McCoughtry