Saints edged further ahead of the Rhinos in the middle reaches of Super League, where, on this impressive showing by both sides last night, they have no business being.
A new era was ushered in at Headingley with a demonstration of the game at its most enterprising. The first of Sky's summer season of Monday night games offered a Grand Final repeat and a chance for the champions Leeds to avenge a 46-6 defeat at Saints earlier this season. No shortage of motivation for either side, then, especially as both of them had already lost five times in a mixed first half of the season.
The Rhinos thought they had made the early breakthrough when Lee Smith completed a long-range attack, only to be brought back for Carl Ablett's knock-on. They only had to wait to the 12th minute to take the lead, Brent Webb supplying Ryan Hall, who beat Tommy Makinson's tackle and passed inside for Danny McGuire. Kevin Sinfield's conversion took him past the 3,000-point mark.
Saints' response was a messy affair, Leeds allowing Lance Hohaia's kick to bounce eccentrically for Jonny Lomax to pounce and Makinson to add the equalising goal.
Saints took the lead for the first time, thanks to Tony Puletua's offload, James Roby's break, carried on by Lomax for Wellens to finish off. It was all level again when Sinfield barged through and Brett Delaney was in support.
Another miracle pass from Puletua to Gary Wheeler almost put Saints in front again at the start of the second half. Instead, it was Jamie Jones-Buchanan's first try of the season, running on to Webb's pass, that gave Leeds the advantage.
Saints came back in style, Makinson taking Michael Shenton's pass and forcing his way over. The first missed goal of the night left Leeds two points clear.
That changed with another beautifully crafted try in the 58th minute, Lomax exchanging passes with Sia Soliola to go over for the second time.
Sinfield was placed on report for a high tackle on Makinson that saw the young St Helens winger taken off on a stretcher. From that penalty, Saints built the pressure and Jon Wilkin went over from a brilliant pass by Roby. Lomax, replacing Makinson, landed the goal, plus a penalty for ball-stealing and an insurance drop goal.
Leeds Webb; Smith, Watkins, Hardaker, Hall; Sinfield, McGuire; Leuluai, Burrow, Peacock, Jones-Buchanan, Delaney, Ablett. Substitutes used Bailey, Clarkson, Griffin, Lunt.
St Helens Wellens; Makinson, Shenton, Wheeler, Meli; Hohaia, Lomax; Perry, Roby, Laffranchi, Flannery, Soliola, Wilkin. Substitutes used McCarthy-Scarsbrook, Puletua, Clough, Flanagan.
Referee S Ganson (St Helens).