Recent slip-ups from both sides have allowed Stevenage take an outright lead at the top of the table, after the hosts drew at Doncaster Rovers last weekend, while the visitors lost 1-0 to Salford City.
Match preview
When Leyton Orient head coach Richie Wellens arrived at the club in March, even he cannot have imagined how quickly he would be able to turn things around.
The O's were sat four points above the relegation zone when the former Leicester City midfielder took over from Matt Harrold, and were on a miserable winless run of 14 league games, picking up just four points from a possible 42.
Hardly six months later, and the manager would be scooping consecutive Manager of the Month awards, having made the best start to a season in the division's history, recording nine wins and a draw from their opening 10 games, with 18 goals scored and just four conceded.
A shock defeat to Newport County brought the unbeaten start to an end, before a frustrating 1-1 draw to Doncaster Rovers last weekend saw the East London club slip to second.
Despite the dropped points, Orient fans will have been watching Paul Smyth's acrobatic goal on repeat, as the club's top scorer continued his fine form with one of the best finishes of his career.
The club have not played in the third tier of English football since 2014, and will be relying on the Northern Irishman's goals if they are to gain promotion once again.
While Leyton Orient could only dream of the automatic promotion places last season, the visitors could not have come much closer to achieving a top-three finish.
A 7-0 win for Bristol Rovers on the final day of last campaign, coupled with a 3-1 victory for Northampton, meant that The Cobblers sacrificed a five-goal advantage to their promotion rivals, ultimately missing out on their season-long objective on goals scored.
Jon Brady's side do not seem to have let their final-day heartbreak affect this campaign, however, storming to eight wins from their opening 13 games, having outscored every other side in the division.
Winger Sam Hoskins has been the main man in front of goal, with 11 goals in 11 appearances so far, including four braces against Colchester United, Crawley Town, Crewe Alexandra and Rochdale.
Like their opponents on Saturday, however, Northampton are winless in their last two, with consecutive 1-0 defeats to Walsall and Salford City representing a disappointing dip in form heading into this table-topping crunch match.
Leyton Orient League Two form:
W
W
W
W
L
D
Leyton Orient form (all competitions):
W
W
W
W
L
D
Northampton Town League Two form:
W
W
W
W
L
L
Northampton Town form (all competitions):
W
L
W
W
L
L
Team News
The hosts have no new injury concerns going into this crucial game, with only long-term absentees Anthony Georgiou and Dan Nkrumah still missing.
Striker Charlie Kelman may return to the starting lineup here, after being dropped to the bench last weekend. Without a league goal in six appearances, the American forward has a point to prove after his rapid start to the season.
For the visitors, there finally seems to be light at the end of the tunnel concerning their injury and illness crisis, with Jon Brady only being able to name six substitutes at Swindon earlier this month.
Centre-back Tyler Magloire will not be available, but both Aaron McGowan and Shaun McWilliams could be fit enough to make the squad.
Leyton Orient possible starting lineup:
Vigouroux; Hunt, Happe, Beckles, James; Mizouni, Moncur, Pratley; Smyth, Kelman, Archibald
Northampton Town possible starting lineup:
Burge; Koiki, Guthrie, Sherring, Lintott; Sowerby, Leonard; Hoskins, Bowie, Pinnock; Hylton
We say: Leyton Orient 2-1 Northampton Town
A very evenly-matched tie between two early high-flyers, it is difficult to predict a clear favourite in this one.
Given the home advantage, however, and the fact that Northampton have conceded in their last four, we can see the home side just coming out on top.