Erin Thorn had 17 points, Seimone Augustus added 16 points and four assists, and Lindsay Whalen scored 13 points for defending champion Minnesota (27-6). The Lynx, who have clinched the No. 1 seed in the Western Conference, open the playoffs at home against Seattle next Friday.
DeWanna Bonner scored 17 points for Phoenix (7-26), which matched the franchise record for losses in a season, set in 2003. The Mercury finish the season Sunday against the Storm.
The Lynx played their starters into the third quarter, extending their lead to 33 after leading 51-34 at the break.
Minnesota swept the four-game season series with Phoenix this season after beating the Mercury 2-0 in the West finals a year ago. Thorn shot 5 for 8 on 3-pointers for the Lynx.
The last-place Mercury, with three of its regulars back from injury, stayed with Minnesota for more than a quarter until the Lynx scored 13 straight points, keyed by Thorn’s back-to-back-to-back 3s midway through the second period, that gave Minnesota a 37-25 lead with 5:18 left in the first half.
Candice Dupree, who missed 21 games this season after knee surgery, had eight points and seven rebounds in 18 minutes for Phoenix, which had reached the Western Conference finals the last three seasons.
Sammy Prahalis, who missed six games with an injured shoulder, had 14 points and eight assists for the Mercury, who have lost six straight.
Olympian Diana Taurasi, who has missed 23 games this season, much of it with a hip flexor, did not play.