Rangers strengthened their grip on second place with a win over St Mirren, despite missing two penalties.
Lee McCulloch's header beat Saints keeper Craig Samson before Sone Aluko missed the hosts' first spot-kick.
Andy Little fired Rangers two up before the break, but Paul McGowan's penalty for St Mirren gave them hope.
Samson saved McCulloch's effort from 12 yards after Saints' Jeroen Tesselaar had been sent off, but Kyle Lafferty converted Rangers' third penalty.
With Celtic having clinched the Scottish Premier League title earlier in the day, Rangers were looking for the win that would take them nine points clear of third-placed Motherwell, who face Hibernian on Sunday.
And Ally McCoist's side were in front less than a minute after kick-off as McCulloch nodded Steven Davis's free-kick home.
Davis picked up a knock and was replaced with Rhys McCabe before Rangers' Maurice Edu was tripped by Steven Thomson, prompting referee Willie Collum to point to the spot.
But Aluko's 14th-minute effort hit the outside of the post on its way out.
Aluko then had a shot blocked by Samson, but Little did beat the keeper with a left-foot shot after the ball deflected into his path.
Allan McGregor made impressive saves to deny Dougie Imrie and Nigel Hasselbaink before the break.
However, grappling by Dorin Goian on Steven Thompson gave Saints the chance to reduce their deficit and McGowan showed composure as he sent McGregor the wrong way from 12 yards on 49 minutes.
No sooner had Saints scored a penalty than they conceded another as Tesselaar was adjudged to have denied Aluko a goalscoring opportunity in the box and was promptly red-carded.
However, McCulloch's spot-kick was well saved by Craig Samson.
The Ibrox side finally converted after referee Collum awarded them a third penalty for Lee Mair's challenge on McCulloch.
Lafferty, who had replaced Salim Kerkar, found the net with an effort similar to McGowan's.
McCulloch tried to add to Rangers' lead late on, but Samson blocked the powerful shot.
Rangers manager Ally McCoist: "we wanted to win the game for everybody - the supporters and the players - so I'm delighted.
"I watched the penalties again and I would have to say that Willie got every one of them correct, spot on.
"It's a remarkable percentage, giving four penalties and getting them all right. That would have to be a big plus for Willie.
"In terms of our percentage in taking them, there is plenty of room for improvement as you can see."
St Mirren manager Danny Lennon: "It's a difficult enough place to come to without giving away three penalties and having a man sent off.
"But I've got to give my players credit - they played some great football.
"And credit to Rangers, their dominance has been taken over by the financial circumstances at the football club. It's great to see Ally and his backroom staff getting three wins on the trot.
"Hopefully they can continue to focus on that and you guys are writing the good things about what this proud club is all about."