Esmael Goncalves had struck first for St Mirren men but despite levelling through the former Rangers frontman, the hosts could not find a winner as they dropped two points to leave them sweating on a top-six place.
Boyd's last SPL goal came on the final day of the 2009-10 season. And the top-flight's record scorer showed his predatory instincts as he smashed home a leveller within two minutes of the restart. The Scottish Communities League Cup winners survived a late penalty call. James Fowler was barged into by David Van Zanten, yet referee Crawford Allan waved play on.
The first chance was wasted by the visitors' Steven Thompson, who blasted over from Gary Teale's corner. Boyd was soon involved, playing in Fowler from a quick free-kick but his midfield colleague was tame with a shot straight at St Mirren goalkeeper Craig Samson, while the 18-cap former Scotland striker then headed over from Borja Perez's corner.
Thompson came within an inch of connecting with Paul Dummett's low cross just before the half-hour mark after the on-loan Newcastle left-back fired a teasing cross into the six-yard box following a clever one-two with Goncalves, who then fired wide himself seconds later.
Killie were then caught out much too high up the pitch. Boyd had chased a hopeful ball from Ross Barbour but was beaten to it by the onrushing Samson. Within seconds the visitors had worked it to van Zanten and the Irishman produced a perfect through-ball in behind the Killie backline for Goncalves to burn past Mark O'Hara before slotting under Cammy Bell.
Two minutes before the interval, the on-loan Rio Ave frontman then muscled beyond Momo Sissoko to blast another attempt but this time Bell palmed it down before Goncalves pushed the rebound wide.
Saints' half-time lead was harsh on Kenny Shiels' men, but with 90 seconds of the restart they were level as Boyd struck. Perez lofted a ball in behind the Paisley defence and Boyd was clinical as he connected well to send the ball past Samson at his near post and register his 165th goal in Scotland's top flight.
The provider of that chance volleyed fractionally wide from Garry Hay's clipped cross while Boyd was denied a second when his header from Fowler's looping cross was stopped by Samson.
St Mirren managed to drag themselves upfield as Thompson teed up Teale with 10 minutes left - but the former Scotland international could only flash a weary effort wide. And the visitors looked out on their feet as Fowler burst into the box in the final minute before being bundled over by last-man van Zanten. It looked a certain penalty but Allan waved Killie claims away.