It's only going to get tougher from here for the No. 5-seeded Phoenix Mercury and No. 6 Chicago Sky.

The WNBA semifinals are tied, 1-1, for each of the best-of-five series underway. Games 3 are Sunday afternoon and include a matinee on ABC.

The No. 1 Connecticut Sun are trying to get past the No. 6 Chicago Sky. The No. 2 Las Vegas Aces are battling with the No. 5 Phoenix Mercury. The final four teams include the season's top three best offenses, top two defenses and only one squad that has won a championship. That would be the Mercury with titles in 2007, '09 and '14.

Only one team not seeded No. 1 or No. 2 has reached the WNBA Finals since the new format was instituted in 2016. And that was the No. 3 Washington Mystics, so the Mercury and Sky could make history with the legitimate upset.

Here is how to watch the best-of-five series and what to watch for as the playoffs continue. This post will be updated after each game with results and key takeaways from each contest.

WNBA semifinals TV schedule

Game 1

Chicago 101, Connecticut 95 2OT (Sky lead, 1-0)

Las Vegas 96, Phoenix 90 (Aces lead, 1-0)

Game 2

Connecticut 79, Chicago 68 (Series tied, 1-1)

Phoenix 117, Las Vegas 91 (Series tied, 1-1)

Game 3: Sunday

Connecticut at Chicago, 1 p.m. ET, ESPN

Las Vegas at Phoenix, 3 p.m. ET, ABC

Game 4: Wednesday

Connecticut at Chicago, TBD, ESPN

Las Vegas at Phoenix, TBD, ESPN

Game 5 (if necessary): Friday

Chicago at Connecticut, TBD, ESPN2

Phoenix at Las Vegas, TBD, ESPN2

The WNBA Finals begin Sunday, Oct. 10 at 3 p.m. ET on ABC.

No. 1 Connecticut Sun vs. No. 6 Chicago Sky (Chicago leads, 1-0)

Game 2: Connecticut evened the series despite four points from its MVP, Jonquel Jones. It was Alyssa Thomas who came alive in the final quarter to create separation from the Sky and avoid going to Chicago down, 0-2. The defense locked down on Chicago's playmaking.

It's ironically the Sun who have been inconsistent and yet to play to their potential so far this postseason when that was Chicago's problem heading into it. The Sun will need more from Jones if they want to get this done in four. A Game 5 seems like it would be an absolute toss-up.

Something to look at in Game 3: the free throw line. The Sun have struggled so far this series and it could mean the difference in a Finals berth.

Game 1: The Sun and Sky took 50 minutes to determine a winner in Game 1, which was played mostly within a possession or two for 40 of those minutes. It's a quick 48-hour turnaround for these tired groups.

Chicago's Courtney Vandersloot became only the second player in WNBA history to hit a triple-double in the playoffs and dished out a playoff-record 18 assists. The Sky had 31 assists on 38 made shots, and when their offense is clicking like that it's hard to stop them. Four players reached double digits and four more were one or two points away.

The Sun's defense will be the focal point for Game 2. They allow on average 69.9 points per game in the regular season, but let up 84 in regulation on Tuesday night. That won't cut it if they want to even the series.

Previously: Chicago won the season series, 2-1. All were in June when Sun were without Jonquel Jones.

Streaks: Connecticut had a 14 consecutive regular-season win streak dating back to July 3. They were 15-1 at home in the regular season. The Sky came in on a three-game winning streak.

Game 2:

How will Chicago handle Jones? The Sky had yet to play a fully loaded Sun team as Jones, the likely MVP, missed time while at EuroBasket. She averaged 19.4 ppg (ranking fourth), 11.2 rpg (first) and 1.3 bpg (10th). Most detrimentally for opponents, she can step back and hit 3s at a good clip.

The Sky will also be faced with Alyssa Thomas, who made her return the last days of the season after recovering from an Achilles injury. Head coach Curt Miller said Monday Thomas has been more aggressive in practice after being a tad timid in those first games back.

What Sky team will show up? Chicago's second-round victory wasn't all too surprising because when this roster plays its best, it's top-four in the league, easily. But there have been gaps and a lack of consistency throughout the year. So far in the playoffs, we've seen the Sky at their best for seven of eight quarters. They'll need to continue that, and be the defensive team we saw at the beginning of the season and playoffs, to advance.

Sun shine on defense: Connecticut has the top-ranked team in defensive rating (93.7) and points allowed (69.9). The Sun lead both categories by a significant margin. The Sky scored 81 and 91 points on them in back-to-back June games, but were kept to 58 a week later in the only game played at the Mohegan Sun arena. In their 14-game win streak, the Sun have allowed on average 64.2 points.

Jones received votes for Defensive Player of the Year and was named to the All-Defensive first team with Briann January. Brionna Jones and Jasmine Thomas were named to the second team.

No. 2 Las Vegas Aces vs. No. 5 Phoenix Mercury (Las Vegas leads, 1-0)

Game 2: Bill Laimbeer quite emphatically insisted Diana Taurasi wasn't injured, and she sure made that seem like reality in Game 2. Taurasi scored a playoff career-high 37 points, hitting eight of 11 3-point attempts, in a demolition of the Aces. The Mercury reached a playoff record 68 points in the first half shooting 76.5% — there honestly wasn't much the Aces could do keep up.

They were out-rebounded, 36-23, but shot around 50%. Their second-ranked defense will have to lock down early to force the Mercury into tough looks, and keep them from gaining momentum.

Game 1: Kelsey Plum and Riquna Williams couldn't be stopped, laying in 25 and 26 points, respectively, to protect home court for a Las Vegas team that didn't look impacted by 10 days off.

The Mercury shot 9-for-31 (29%) from 3-point range, but the biggest focus is on Diana Taurasi. After pulling up grimacing hard in the fourth quarter, she was subbed out and the broadcast was prompted to report on her availability as if she might be done for the night. Taurasi, unsurprisingly, came back in and finished with 20 points, six assists and five rebounds.

The other factor to consider for Phoenix: Cambage played only one-quarter of the contest as she gets her cardio back following a bout with COVID-19.

Previously: The Aces won the season series, 2-1. That includes a 84-83 win on the final day with much of the starters getting limited minutes. It was the last game the Aces played.

Streaks: The Mercury lost three to skid out of the regular season, but won both playoff elimination games. The Aces came in on a four-game winning streak.

Can Diana Taurasi keep going? The league's all-time points leader limped and grimaced her way through much of the second-round overtime win against the Storm. It's tough to imagine that gets better with the Mercury playing about every other day in the semis. Still, Taurasi had 14 points, four rebounds, five assists and a steal while hitting clutch shots when needed. Her veteran leadership and energy is invaluable and head coach Sandy Brondello also cited her calmness in keeping the team steady.

BG vs. Liz: The Mercury's 6-foot-9 center Brittney Griner (20.4 ppg, 9.7 rpg) will face the Aces' 6-foot-8 Liz Cambage (14.2 ppg, 8.2 rpg) in an evenly matched post. Griner scored a season-high 33 points and 10 rebounds in the Mercury's one win. She had 27 and 11, respectively, in the first game. Cambage neared double-doubles in those contests, but has more offensive weapons around. The regular-season finale was her first back after contracting COVID-19, and she said she lost her cardio levels during it.

Big 3 vs. Everybody: The Mercury have mostly relied on their Big 3 of Griner, Taurasi and Skylar Diggins-Smith. They are the only Phoenix players averaging double-digits and combine for 65% of the team's scoring. They'll need more, like what they received from Sophie Cunningham in the first round.

The Aces are the opposite. This is a team that has incredible depth behind two-time Sixth Woman of the Year Dearica Hamby and Kelsey Plum, who is a lead candidate for this year's award. The team set a record with seven players in double-digit scoring. Plum, Jackie Young, Chelsea Gray and reigning league MVP A'ja Wilson all averaged between 15.3 and 16.5 points over the three games against the Mercury.