Gers did have chances to bury their rivals and move 12 points ahead of the Parkhead side in the SPL.
Nikica Jelavic celebratesBut they couldn’t take them and paid the price deep in injury time when former Ibrox player Steven Thompson equalised.
Lennon will have been far happier with the end result than Ally McCoist, who will have seen this game as a chance to pile more pressure on the club’s Old Firm rivals.
Instead, they remain 10 points clear of them rather than 12 and are now just seven beyond second-top Motherwell.
With Steven Naismith available again, he came back into the team as McCoist made two changes to the side which beat Hibernian 1-0 a fortnight ago.
Alejandro Bedoya dropped out as a result, with Lee Wallace also coming in for Sasa Papac at left-back as the Bosnian spent the day in his sick bed.
With Celtic dropping two points at Kilmarnock earlier in the day, there was a real incentive for Gers to win and stretch their lead in the league over the Parkhead team to 12 points.
And Kyle Lafferty had the first chance of the day, drawing a really good save from Craig Samson after he connected well with Gregg Wylde’s corner.
Dorin Goian also had a go but his attempt was about as horrific as you can get, with his half volley ballooning high and wide over the bar.
Saints have won praise for the good football they have played this season but in the early stages they looked nervous in defence.
That meant there was space for the hosts to try to exploit them and captain Steven Davis wasn’t far away with a 25-yard drive.
Gers’ movement coming forward was really good, with the skipper, Naismith and Nikica Jelavic all heavily involved.
But it was a Maurice Edu header which almost broke the deadlock and his attempt from a Davis corner was only inches off target.
Steven NaismithMoments later, the visitors had their own opportunity to strike as Allan McGregor flapped at a corner.
Thankfully Jim Goodwin’s low drive, deflected off Steven Thomson, trickled wide when it seemed it might sneak in.
Nevertheless, that chance signalled a brief change in the balance of play, with the Buddies clearly growing in confidence.
As they began to enjoy more possession, Nigel Hasselbaink might have done better with a shot which he fired straight at McGregor from a tight angle.
There was also a chance for the Paisley outfit to trouble Gers when Wallace fouled the Dutchman but they didn’t make the most of their free kick on the right.
Saints were causing concern for home fans and their build up play was nice but again their finishing let them down as Paul McGowan’s clip was weak.
It took too much time for Rangers to emerge from their slumber but when they finally did, they very nearly ended the first half ahead.
Good play on the break nearly led to Wylde setting up and opener for Davis but he shot a yard past and with that, it was still goalless at the midway point.
Rangers looked a bit brighter at the restart, with Naismith going close from the edge of the area.
His effort was a precursor for the goal which finally put the SPL champions ahead – and it was Jelavic who got it with his seventh of the season.
The strike was largely down to good work from Lafferty, whose persistence eventually allowed play to open up for him to cross low into the mix.
His ball was only partially cleared and Jelavic didn’t need a second invitation as he rattled home from 12 yards.
Kyle LaffertyHaving an advantage gave the Light Blues a huge lift and they went looking for a second – but within seconds were almost pegged back instead.
Thompson was played in on goal and homed in on McGregor but Steven Whittaker slid in – not for the first time in the game – to block with a last-gasp tackle.
Marc McAusland then headed the resulting corner inches wide and suddenly nerves began to fray again.
Back came Rangers, with Whittaker’s lift upfield finding Lafferty but his attempt rolled straight in keeper Samson’s arms.
The game was opening up and both teams were finding gaps so while the clock was ticking down, it still looked as though either side could win.
Juanma Ortiz and Lee McCulloch came on for the hosts, with the former having a shot deflected away and Jelavic heading wide.
Naismith was also wasteful as he took on a chance to shoot himself when Lafferty was better placed to do something with the ball.
Rangers were now creating more opportunities but couldn’t get that second which would kill the game, with Samson saving well from Davis.
And that ensured the last few minutes would be tense and Goian didn’t help matters with a sliced clearance that almost looped over McGregor and in.
St Mirren could sense a point was there for the taking and deep into injury time, they got the share of the spoils their unrelenting attitude deserved.
Jelavic and Whittaker both had chances blocked and it seemed that wouldn’t matter as Gers were still clinging on.
But in one final surge forward, the Buddies levelled three minutes into added on time as Thompson poked in to spark bedlam in the away end.
Home fans booed at the final whistle as the small pocket of supporters in the Broomloan Corner celebrated.
In truth, however, their joy was merited as the nine-match winning streak Rangers had been enjoying in the championship came to an end.