Twice the visitors faced a 12-point deficit against a Leicester outfit that was on a four-match winning streak coming into the game. But twice they came back, and with two tries in as many minutes just past the hour Saints put themselves into a winning position.
But just as there had been at Thomond Park there was a sting in the tail as Horacio Agulla scored a try with three minutes to go to secure the points for the Tigers.
The Argentine had been involved in just about every crucial moment throughout the game. Somewhat lucky to have stayed on the pitch following his involvement a first half melee which had seen Alesana Tuilagi and Tom Wood be red carded, the wing also made a mess of clearing the ball up to allow Chris Ashton to put Phil Dowson over for the Saints' third try.
Ashton himself was also a man in the middle of the action. As well as setting up Dowson's score with his sheer pace and determination in chasing his own kicks ahead, the Wiganer scored his team's first try and it was his tackle on Tuilagi that sparked the aforementioned touchline fracas.
The Samoan's 14th-minute run had been typical, bouncing Ashton's first attempt off and powering into the visitors' danger zone. But when Ashton pulled Tuilagi into touch with his second attempt players from both teams came piling in. When everything had calmed down Tuilagi and Wood had been singled out for attention and spent the rest of the afternoon on the sidelines.
To that point there had only been six points scored, shared between fly halves Ryan Lamb and Toby Flood, but already there had been enough action to keep supporters and journalists alike talking for hours.
Now missing a key man at the set piece and breakdown, Saints struggled to settle, and with Matt Smith's try at the end of the first quarter Tigers were in front for the first time. Even this was somewhat controversial. Smith's power had taken him over the line, but despite replays seeming to show that the ball had been grounded on the dead ball line TMO David Matthews awarded the try.
There were no such talking points arising from Leicester's second try, Steve Mafi powering past several Saints on his way to the score. Tigers' finishing was in contrast to the visitors, for whom few things went right when they got into the home 22.
There were plenty of promising signs in the build-up play, Lamb looking dangerous with ball in hand and the backs looking to spread the ball wide at every opportunity. But the crucial 50/50s were going Tigers' way, and although Lamb kicked a second penalty it was obvious that Saints were going to have to turn those half-chances into points if they were going to get anything out of the game.
The second half threw up as many talking points as the first. But these would come from some outstanding rugby from both teams that brought both chances and tries at both ends of the field.
A Flood penalty took Tigers 18-6 clear, but with 46 minutes on the clock the visitors had exactly what they needed with Ashton's try.
The Wiganer had started the move from deep in his own 22, running back a Billy Twelvetrees kick with interest. Ashton intelligently fed Ben Foden to keep the play alive, and a couple of phases later the full back repaid the favour by putting the winger away for the score.
At 18-11 Saints were back in the contest, but with Lamb's kicking for once failing him at both the conversion and a subsequent penalty they were still being held at arm's length by the Tigers, who should have gone further ahead just before the hour.
Flood's show and go had taken him through the line, with Saints rescued by the fly half's slip. Leicester worked the phases but with the whitewash in sight Saints forced a turnover which sparked a move that almost brought a score at the other end.
Soane Tonga'uiha, Samu Manoa and Brian Mujati took play up to the 22 before Courtney Lawes put Tom May away with an outstanding pass. May took the long route to the left wing and for all intents and purposes looked to be away. Mafi had other ideas and his tap tackle proved crucial by bringing the centre down and allowing the defence to scramble back.
Then just as Saints looked to be getting the momentum firmly behind them a fumble handed Tigers the initiative. Julian Salvi scooped up the loose ball, the green shirts swarmed forward and Ben Youngs reached out to grab his team's third try.
Saints needed to strike back immediately, which they did when May finished off some good team play. But when Dowson crossed 120 seconds later, with Stephen Myler adding both conversions, Saints had the lead for the first time in an hour and with just two points separating the teams the packed Welford Road was set for a grandstand finish.
And so it proved.
Having been the sinner in handing Saints the lead, Agulla then scored the clinching try. Ironically it came from a sustained period of Saints attacking. With Tigers on the ropes Myler sent a chip through the middle straight to George Chuter. With men over on the left the Tigers put the ball through the hands, Agulla was over and the points were Leicester's.
REFEREE Wayne BARNES
5mins SAINTS Pen Lamb 0-3
12mins TIGERS Pen Flood 3-3
14mins TIGERS Red card Tuilagi
14mins SAINTS Red card Wood
21mins TIGERS Try Smith 8-3
33mins TIGERS Try Mafi Con Flood 15-3
36mins SAINTS Pen Lamb 15-6
40mins TIGERS Miss DG Flood
40mins TIGERS Miss pen Flood
HALF-TIME TIGERS 15 SAINTS 6
42mins TIGERS Pen Flood 18-6
46mins SAINTS Try Ashton 18-11
52mins SAINTS Miss pen Lamb
60mins TIGERS Try Youngs 23-11
64mins SAINTS Try May Con Myler 23-18
66mins SAINTS Try Dowson Con Myler 23-25
76mins TIGERS Try Agulla Con Flood 30-25
FULL-TIME TIGERS 30 SAINTS 25