With the Overwatch League down to the final four teams in their Inagural Season, we brought in Blizzard commentators Erik "DoA" Lonnquist and Christopher "MonteCristo" Mykles to the studio to help our Tyler "Fionn" Erzberger break down the matchups. (5:36)

The first two series of the inaugural Overwatch League playoffs are in the books, with the Philadelphia Fusion and London Spitfire advancing to the semifinals over the Boston Uprising and Los Angeles Gladiators, respectively. In both cases, the lower-seeded team won in 2-1 fashion.

Fusion ends Uprising's season

With a stable roster of six players, the Uprising were able to take the second match of the series 3-1 against the Fusion. Boston was able to overcome significant disadvantages on Hanamura and Lijiang Tower, maps on which Boston had a losing record in the regular season. The Fusion attempted a brand-new team composition on Junkertown, with Park "DayFly" Jeong-hwan playing on Bastion, but the Uprising were able to hold firm and secure the map.

Match 3 of the series introduced a new map selection system where the losing team from the previous map would decide the next map of play. The ability to make that decision backfired significantly for the Uprising. When it came to Map 4, which wound up being the deciding map of the series, Boston had the ability to choose between Hanamura (2-8 in the regular season) and Volskaya Industries (10-0). The Uprising chose Hanamura, which they had won in Match 2 of the series, but Boston could not repeat its previous success.

Despite capturing the opening map in Match 3, the Uprising fell in the series. Boston was 20-1 when winning the first map of a match in the regular season (the lone loss was to Philadelphia).

London pulls a series reverse-sweep

The Spitfire dropped the first match of the series against the Gladiators 3-0, and at times London looked completely lost. London was able to rally on the second day of competition, though, and pulled off six consecutive map wins in back-to-back match sweeps to win the series 2-1 and earn a date with the Los Angeles Valiant in the semifinals.

After Match 1, the story was that the Gladiators looked impressive despite the absence of superstar tank Baek "Fissure" Chan-hyung. On Saturday, Fissure's absence cost the Gladiators, as they failed to win a single map. The two match sweeps were unexpected for the Gladiators, who had been held without a map win only twice since the beginning of Stage 2. Much of Los Angeles' season was defined by Fissure's transfer to the team and subsequent absence in the playoffs. Ultimately, six of the eight matches in which the team was held without a map win came when Fissure was not in the lineup.

London was able to get off to strong starts on escort maps Dorado and Junkertown against the Gladiators. On Dorado, Park "Profit" Joon-yeong spent most of the match on fire as Brigitte. His 1,452 player rating on Brigitte during the regular season was highest in OWL among players who played the character at least an hour onstage. On Junkertown, Hong "Gesture" Jae-hee consistently used Orisa's halt ability to confirm kills with Hanzo's ultimate on London's offensive run through the map. Per Winston's Lab, he was the highest-rated Orisa in OWL Season 1.

Hong "Gesture" Jae-hee, left, shakes hands with London Spitfire teammate Choi "Bdosin" Seung-tae during the Overwatch League quarterfinals at Blizzard Arena on Saturday in Los Angeles. Robert Paul/Provided by Blizzard Entertainment

Semifinal 1: Fusion vs. Excelsior

The Fusion were one of five OWL teams to get a regular-season win against the Excelsior, and they nearly defeated New York in the Stage 2 playoff finals but suffered a reverse-sweep loss. However, the Fusion have dropped four consecutive matches to the Excelsior since winning the first meeting between the teams.

In the four regular-season meetings between the teams, the Excelsior were able to secure a win on the control map. The only time the Fusion were able to get a win on control was in the Stage 2 finals, where the Fusion won on Lijiang Tower.

As has been the case the entire season in the OWL, this series will likely be decided by Zenyatta play. New York has Bang "JJoNak" Sung-hyeon, the league's MVP and by far its best Zenyatta player (1,263 rating). The Fusion will counter with Isaac "Boombox" Charles, who ranked as the worst Zenyatta player among Zenyatta mains in the OWL.

Semifinal 2: Spitfire vs Valiant

The Spitfire and Valiant played an incredibly close regular-season series. In three matches, the Spitfire held a 2-1 edge, but both of their wins required a tiebreaker map. Overall, the teams were separated by one map (in favor of the Spitfire) across the three matches.

Following the Spitfire's six-map win streak to finish off the Gladiators, it's difficult to determine which of these teams should be considered a favorite. If the second half of the season is any indication, the Valiant should be considered significant favorites. In the last two stages of the season, the Valiant went 16-4, tied with the Excelsior for the best record in the OWL. In that same time, the Spitfire were 9-11 and nearly cost itself a spot in the postseason.

With the series likely to be close, any small difference could decide the series. The presence of two potential escort maps could tip the scales in the Valiant's favor. Los Angeles was 14-6 on Dorado and Junkertown combined, the second-best record in OWL (the Excelsior went 15-5). The Spitfire were 12-8 on those maps, but they were 3-7 in the second half of the season.