The Fever (2-16) won their first regular-season game at the Target Center since 2011.
Achonwa shot 7 of 10 from the field and tied her career-high with three blocks. Rookie Victoria Vivians had 13 points — her fifth consecutive game scoring in double figures — and Cappie Pondexter added a season-high 12 points for Indiana.
Pondexter, who was signed by Indiana on Sunday, converted a 3-point play to spark an 8-0 run that gave the Fever a 59-51 lead when Achonwa hit a jumper with 5:53 to play. Maya Moore hit a 3-pointer about a minute later to pull the Lynx within four but Vivians answered with a deep 3 as the shot clock expired as Indiana scored 10 of the final 12 points.
Rebekkah Brunson, the only Minnesota player to score in double figures, had 13 points. The Lynx (10-7), who shot just 32.8 percent from the field, had their seven-game win streak snapped.