Rangers kept the pressure on second-placed Aberdeen, as goals by Kenny Miller and Jon-Miquel Toral sealed three comfortable points in their 2-0 victory over Partick Thistle.
In a contest between two in-form teams, 37-year-old Miller headed the first six minutes before the break, while Toral added a second early in the second half.
The result took Rangers' unbeaten run to eight games, while inflicting only a second defeat in 11 on Thistle.
However, the visitors rarely threatened to secure what would have been a first victory over Rangers in their last 25 meetings - going back to May 1993.
During a dismal first 25 minutes, the only serious effort was fashioned by midfielder Toral, whose shot from outside the box flew high and wide.
The same player had another attempt a few minutes later but, once again, failed to test Thistle 'keeper Tomas Cerny, who was finally called into action in the 36th minute when he saved a Danny Wilson header.
Another Toral shot was cleared off the line before the deadlock was finally broken in the 39th minute. From James Tavernier's cross, Miller headed the hosts in front to collect his 12th goal of the season.
The visitors managed to conjure up their first shot of the match through Adebayo Azeez with 41 minutes on the clock, while home 'keeper Wes Foderingham was at last asked to make a save, stooping low to deny Ryan Edwards from a tight angle.
Rangers continued to dominate after the break, with Miller firing wide from 25 yards and Tavernier heading past a post from inside the box.
And it was no surprise when they extended their lead nine minutes into the second half, with the industrious Toral latching on to Emerson Hyndman's assist to find the bottom right-hand corner of the net from 10 yards - for his first league goal of the season.
Only a pair of good saves from Cerny prevented the hosts from extending their lead during the closing 30 minutes, with the Czech 'keeper denying Miller and Waghorn.
With five matches remaining, Rangers trail Dons by nine points, with the teams scheduled to meet at Ibrox in the penultimate game of the season in mid-May.
As for Partick, they will end the season in the top six for the first time in 36 years.