Betfred Super League
St Helens (6) 22
Tries: Makinson 2, Lomax, Batchelor Goals: Percival 3
Leigh (6) 12
Tries: Gildart, Mulhern Goals: Reynolds 2
St Helens kept pace with Super League leaders Catalans Dragons thanks to a hard-fought win over Leigh Leopards.
Leigh edged ahead after nine minutes when Saints failed to pick up Oliver Gildart who touched down with ease.
Tommy Makinson hit back either side of the break for the hosts with Jonny Lomax giving them a 10-point cushion.
Robbie Mulhern worked on to Edwin Ipape's offload to set up a tense finale but Joe Batchelor wrapped up the win for Saints in the closing stages.
The win for St Helens means they are level on points with Les Dracs - with Wigan two points behind in a thrilling chase to this season's League Leaders' Shield - with two regular season games remaining.
Leigh, meanwhile, remain in fourth but their hopes of a Challenge Cup and League Leaders' Shield double ended with the defeat.
St Helens levelled just before the midway point of the first half and it came as a string of passes from Lomax and Batchelor stretched Leigh's defence, with Makinson crossing over for his 21st try of the season.
Leigh produced some stunning defence to keep Saints at bay in a frantic end to the second half, with Louie McCarthy-Scarsbrook thwarted in his efforts to race to the line as the half-time hooter sounded.
Leigh had threatened after the restart when Zak Hardaker dived to the line but was held short, and Makinson made them pay when he touched down for another try 10 minutes into the second half.
The game flipped into Saints' favour when Lomax pulled off a sensational dummy to wrongfoot the Leigh defence and race in to score.
There was late drama to come, however, as Mulhern's score pulled Leigh back into the game and the visitors thought they had stolen victory late on when Joe Mellor raced over, causing raucous celebrations from Leopards owner Derek Beaumont who was watching on at a sweltering Totally Wicked Stadium.
However, referee Chris Kendall consulted with video referee Marcus Griffiths and the try was chalked off for offside in the build-up, and St Helens then added salt to Leigh's wounds as Batchelor crossed swiftly after the hosts won back possession from a careless knock-on.
St Helens head coach Paul Wellens told BBC Radio Merseyside:
"It was obviously an important game for us that we needed to win but I think it was a game with great intensity.
"When we think of what lies ahead in terms of play-off games, the types of challenges we'll face, that was a nice blueprint.
"I thought Leigh were excellent in the way they came and played committed, energetic and worked hard for each other and made it really difficult for us, as we did for them, and that's what made it such a good game.
Leigh Leopards boss Adrian Lam told BBC Radio Manchester:
"I loved every second of the game. I thought it was absolutely brilliant. I loved our energy but we didn't get our rugby together. The way they turned up for each other was outstanding.
"It was as we thought it would be. They're a physical team and they can bully you if you don't get the first part right. I thought we got bashed and we bashed them.
"It was a semi-final-feeling game with the intensity and it was very physical and I loved every bit of it."
St Helens: Welsby; Makinson, Percival, Davies, Bennison; Lomax, Dodd; Lees, Roby, Knowles, Mata'utia, Batchelor, Bell.
Interchanges: McCarthy-Scarsbrook, Royle, Delaney, Mbye.
Leigh: O'Brien; Briscoe, Chamberlain, Hardaker, Gildart; Reynolds, Lam; Amone, Ipape, Mulhern, O'Donnell, Hughes, Davis.
Interchanges: Mellor, Halton, Nakubuwai, Wardle.
Referee: Chris Kendall.