Mark Warburton insists newly-crowned champions Rangers must now build on their position of strength if they want Steven Gerrard to lead them into a dynasty of dominance over Celtic.
Warburton was the man who guided the Ibrox side back into the top flight in 2016 with their successful Championship promotion campaign.
But the Light Blues supporters had to wait another five years for Gerrard's team to finally end their decade-long wait for a Premiership crown.
Having pulled off a shock Scottish Cup semi-final win over Celtic when they were still a Championship outfit, Rangers fans expected Warburton's team to launch an immediate title bid.
But the Englishman learned to his cost just how big the gulf in quality there was as he came up against Brendan Rodgers' new-look Hoops for the first time at Parkhead five months later.
They suffered a humiliating 5-1 drubbing and ended the campaign in third place, a massive 39 points behind Rodgers' Invincibles.
It has taken millions of pounds and several transfer windows for Gers to have at last overtaken their bitter rivals again – but Warburton warned now is not the time to relax.
"I'm delighted for the blue side of Glasgow, I'm delighted for Steven and his staff and all the friends I know at the club," the QPR manager told Sky Sports News. "I know what it means to Rangers. They have been through so much as a club over the last 10 years from the relegation, the fightback to getting back into the Premiership.
"They have had to close that gap on Celtic which was so clear with the financial disparity.
"They have done that in a solid and steady way.
"We saw the fightback and our own Lee Wallace was hugely pivotal in that and getting the club back up.
"They got promoted back to the Premiership but then there was the need to close the gap.
"They were up against a team that was dominant, packed with internationals, had Champions League every year and that financial gap was huge.
"They have had to close that gap and it can't happen in 12 or 18 months. It takes time.
"But they have done that and over the last two, three, four years they have closed the gap, built the playing squad to a level where it's now at the top of Scottish football and can compete in Europe as well.
"It's been a very sound achievement but what they have to do now – and Steven will be the first to say this – is build on this success.
"I'm sure Steven will be pushing the board and Ross Wilson (Rangers sporting director) to get ever better players in and keep strengthening that position at the top of Scottish football and in Europe as well."
Gers fast-tracked summer moves for Aberdeen winger Scott Wright and Bournemouth defender Jack Simpson ahead of the January transfer deadline.
Cherries midfielder Nnamdi Ofoborh is also making the move north at the end of the season.
Warburton added: "They have got a very strong squad. They found with Celtic that when you've got that momentum and you develop a squad you can build a gap.
"Right now they will be keen to make sure that gap is as wide as possible by the end of the season and lay a marker down that they can build on.
"That's the key. You've got to keep building, adding quality and keeping it fresh, keep moving forward.
"There's no doubt Steven, Gary McAllister and the rest will be very keen to do that.
"They've got their rewards this season and there are a number of points still to play for and the Europa League too, so the ambition is still there.
"But it's a fantastic achievement and I'm delighted for everyone concerned at Rangers."
