Swindon hold the advantage in their Sky Bet League One play-off semi-final with Sheffield United as Nathan Byrne inspired a 2-1 first-leg win at Bramall Lane.
But a big United performance can still keep Wembley hopes alive on Monday.
United may have to find a solution to Byrne.
His trickery wreaked havoc with the Blades all evening.
But he left his biggest impact until the last moment as he struck a winner in the fourth minute of added time.
The winger had earlier won a penalty, which Ben Gladwin missed, and then set up Sam Ricketts early in the second half which cancelled out Kieron Freeman’s opener for the Blades.
It means Mark Cooper’s men go into Monday’s second leg on home soil knowing they only need a draw to book a place at Wembley and put themselves 90 minutes away from the Championship.
In contrast defeat represents a disappointing night for the Blades, who were left seething with a string of decisions by referee Darren Bond, as they bookended the game with dominant spells, but only had Freeman’s 19th-minute opener to show for it.
They must now travel to the County Ground and win or they will be consigned to an eighth unsuccessful play-off campaign and a fifth year in the third tier.
Preston put the disappointment of missing out on automatic promotion behind them with a 1-0 victory at Chesterfield in their first leg.
Jermaine Beckford scored the only goal of the game early on for the team who surrendered second spot on the final day of the regular season.
The goal came during Preston’s only real spell of sustained pressure, while Chesterfield could not make the most of the numerous occasions they were on top and it was a frustrating night of near-misses for Paul Cook’s side, who are looking for back-to-back promotions after winning League Two 12 months ago.