Match ends, Chesterfield 0, Preston North End 1.
Jermaine Beckford's early goal at the Proact Stadium put Preston North End in control of their League One play-off semi-final with Chesterfield.
Preston, who narrowly missed out on automatic promotion on Sunday, made the perfect start as Beckford received Chris Humphrey's pass and lobbed over goalkeeper Tommy Lee.
Chesterfield dominated the second half but were unable to find an equaliser.
The second leg is at Deepdale on Sunday at 12:15 BST.
Preston have failed to win promotion via the play-offs in their previous nine attempts but are now in a strong position to progress to the Wembley final on 24 May.
The major talking point came just moments after half-time, when Spireites midfielder Jimmy Ryan appeared to elbow Paul Gallagher in the face, but both players were shown yellow cards.
The clash came after a first half full of tension in which there was another heated exchange between both sets of players and a further fracas in the tunnel at half-time.
The game had hardly settled down from the pre-match excitement when the visitors found themselves a goal in front through Bolton loanee Beckford.
Chris Humphrey played what seemed an innocuous pass through to the striker, but the Chesterfield defence left him unmarked as he calmly slotted the ball into the net from 12 yards.
The first half flowed from end to end, with League One's top scorer Joe Garner shooting straight at Chesterfield goalkeeper Lee from a tight angle and Dan Gardner forcing a fine save from Sam Johnstone, though there were few clear-cut chances.
Chesterfield came out revitalised after the interval and went close through Gary Roberts' fine run and shot and Ollie Banks' skied effort, but the Lilywhites' defence held firm and they claimed only their fourth win in 22 play-off games.
Chesterfield manager Paul Cook:
"After the disappointment of conceding early on, I thought we were terrific.
"If they had gone on and got a second goal, it would have left us with a mountain to climb, but that is not the case. At 1-0, the next goal in the tie is huge and we believe we can get it.
"It was a great night for our players because when you go up against these teams you can get found out, but that certainly never happened to us.
"We've got to believe in what we do. I do, our players do and our supporters do as well. I must say a big thank you to all our fans."
Preston boss Simon Grayson:
"There was a bit of criticism flying around at the weekend but we've shown a lot of spirit and character and when we've had to defend we have.
"We've put bodies on the line, made blocks and done what defenders are supposed to do. As a team, we worked extremely hard to stop the opposition.
"The players should have been given another opportunity. For large parts when we've had a setback this season we've always responded in the right manner and we've done that tonight.
"We are pleased that we have done well tonight but we aware that we've not done anything yet until Sunday."
- 8RyanBooked at 49mins
- 10O'SheaSubstituted forGnanduilletat 88'minutes
- 7GardnerSubstituted forBanksat 77'minutes
- 12GallagherBooked at 48minsSubstituted forKilkennyat 79'minutes
- 3LairdSubstituted forWoodsat 79'minutes
- 10BeckfordSubstituted forRobinsonat 87'minutes
- Mark Haywood
- Shots on Target
Second Half ends, Chesterfield 0, Preston North End 1.
Attempt missed. Daniel Jones (Chesterfield) left footed shot from outside the box is high and wide to the left.
Attempt blocked. Sam Morsy (Chesterfield) right footed shot from the centre of the box is blocked.
Corner, Chesterfield. Conceded by Bailey Wright.
Foul by Oliver Banks (Chesterfield).
Daniel Johnson (Preston North End) wins a free kick in the defensive half.
Substitution, Chesterfield. Armand Gnanduillet replaces Jay O'Shea.
Substitution, Preston North End. Callum Robinson replaces Jermaine Beckford.
Attempt missed. Joe Garner (Preston North End) right footed shot from the right side of the box misses to the right. Assisted by Daniel Johnson.
Offside, Preston North End. Jermaine Beckford tries a through ball, but Joe Garner is caught offside.
Tendayi Darikwa (Chesterfield) wins a free kick in the defensive half.
Foul by Jermaine Beckford (Preston North End).
Attempt missed. Oliver Banks (Chesterfield) right footed shot from the right side of the six yard box misses to the right. Assisted by Sam Clucas with a cross.
Substitution, Preston North End. Neil Kilkenny replaces Paul Gallagher.
Substitution, Preston North End. Calum Woods replaces Scott Laird.
Substitution, Chesterfield. Oliver Banks replaces Dan Gardner.
Attempt saved. Gary Roberts (Chesterfield) right footed shot from the left side of the box is saved in the bottom right corner.
Delay over. They are ready to continue.
Delay in match Thomas Lee (Chesterfield) because of an injury.