Bottom club Ards picked up their first away point of the season by coming from behind to hold leaders Linfield.
The Blues took the lead through Jamie Mulgrew's shot in the 17th minute but Ards hit back quickly to equalise when Mark McClelland forced the ball in.
Philip Lowry scored from close-range for Linfield who went 3-1 up when Andy Waterworth drilled in a low shot.
Former Blues player David Armstrong got the second for Ards before half-time and Steven Gordon got a late equaliser.
The result means Linfield are now five points clear of second-placed Cliftonville.
In the second half Linfield's Ivan Sproule had forced a fine save from keeper Graeme McKibben while Ards central defender James Cully missed a good chance.
Ards boss Niall Currie made some attacking substitutions and his side never gave up hope of salvaging something from a tough fixture.
They got their reward when substitute Gordon drilled home from about 12 yards when the ball somehow arrived at his feet from after a long throw-in.
It was a surprise result for Currie's men, coming less than a week after they had been dumped out of the Irish Cup by Championship Two side Armagh City.
Ards, 41 points behind Linfield in the league table, looked to be heading for another defeat when Mulgrew scored the opening goal.
Matthew Tipton's pass picked out Mulgrew who ran on to fire in from about 10 yards.
However, Ards got level within two when home keeper Jonathan Tuffey made a mistake with an attempted clearance and the ball fell for McClelland to score.
Lowry then forced in his seventh goal of the season on 26 minutes after Waterworth's ball in had come off Ards man David Gibson.
Waterworth scored himself in the 39th minute running on from Michael Gault's back-heel and beating several defenders before shooting past McKibben.
Ards pulled a goal back before the break when Armstrong bundled the ball over the line and they grabbed their deserved point through substitute Gordon.