The hot-shooting Chicago Sky have opened the best-of-five WNBA Finals with a 91-77 win at the Sandy Brondello-coached Phoenix Mercury.

The Sky withstood Phoenix's fast start and took control with a 21-2 run spanning halftime and then led by as many as 23 points in the final quarter.

Kahleah Copper scored 22 points while Allie Quigley added 18 and Candace Parker 16, among six Sky players in double figures

Game 2 is on Wednesday in Phoenix.

The Mercury's Australian coach Brondello was unable to call on guards Kia Nurse (torn ACL) and Sophie Cunningham (left calf strain), and the lack of depth seemed to hurt the hosts against one of the WNBA's best offensive teams.

Brittney Griner had 20 points and Diana Taurasi 17 for the Mercury, who pulled within eight late before running out of steam and time, while Opals forward Alanna Smith played just four minutes for Phoenix.

The 2021 WNBA Finals is the first for both franchises since the Mercury swept the Sky in 2014.

It's also a showdown between two of the sport's all-time greats still at the top of their games.

A three-time WNBA champion and the league's all-time leading scorer, the 39-year-old Taurasi was voted the greatest player in the league's 25-history by the fans in a ceremony before Game 1 of the finals.

Parker, a two-time league MVP, returned home to Chicago this season after playing her first 13 seasons in Los Angeles.

The 35-year-old was honoured as one of the WNBA's greatest players during the pre-game ceremony.

Taurasi kick started Phoenix's hot start to the final with two early 3s, helping the Mercury build an early nine-point lead.

Parker led the Sky back, scoring 11 first-half points while keying a late second quarter 17-0 run that put Chicago up 46-35 at halftime.

Chicago stretched the lead to 17 in the third quarter before Phoenix went on a 10-2 run to pull within 52-45.

That's as close as the Mercury would get.

The Sky continued to drop in shots, pushing the lead to 86-66 midway through the fourth quarter before withstanding a late run by Phoenix's reserves.