Edinburgh edge Connacht
Two chargedowns bookended an Edinburgh performance that saw them claim a fifth straight Pro14 victory, Dougie Fife giving his team the lead in the blink of an eye before Weir, who also kicked three penalties, helped Richard Cockerill’s troops run out winners.
Success at the Sportsground also means that Edinburgh have now defeated all four Irish provinces in 2017-18.
The visitors got off to a rip-roaring start by going over with 10 seconds on the clock.
Connacht received possession from kick-off but Tiernan O'Halloran's attempted boot forward was charged down by John Hardie, with Fife winning the race to the redirected ball, crashing over the line to put his team on the board in a flash.
A Jaco van der Walt penalty put Edinburgh 8-0 up but with 12 minutes on the clock, Connacht hit back with a well-worked move, Magnus Bradbury feeding the ball to O’Halloran to blaze forward and dot down, Jack Carty adding the extras.
In the 17th minute, Connacht got their noses in front with their second score of the game, turning over possession from the breakdown before patiently carving out an opportunity to bid for the tryline, Carty turning provider for Thomas Farrell to go over, the former converting.
Momentum would swing back in the other direction shortly afterwards however as Edinburgh burst back into life, swept the ball out to the left flank and teed up Duhan van der Merwe to claim his third try in two matches.
A Carty penalty that made it 17-13 would prove to be the final act of the first period and in the opening throes of the second, the two teams largely struggled to break each other down.
It took until just after the hour mark for the scoreboard to be affected again, Weir bisecting the posts to haul his side back to within a point of their hosts but then, back came Connacht.
The home side went on the offensive and drove their way to the whitewash, with Finlay Bealham eventually sneaking over to make it 22-16.
Weir hit another penalty to keep the contest finely poised and then the fly-alf provided a decisive turn.
The 26-year-old gave chase after charging down a kick from Craig Ronaldson and the rebound left him with time and space to seize upon the loose ball for his team's third try of the game, Weir adding the extras before booting a last-gasp penalty to round things off.
Tries: O'Halloran, Farrell, Bealham
Cons: Carty 2
Tries: Fife, Van der Merwe, Weir
Pens: Van der Walt, Weir 3
Connacht: 15 Tiernan O’Halloran, 14 Niyi Adeolokun, 13 Eoin Griffin, 12 Tom Farrell, 11 Matt Healy, 10 Jack Carty, 9 Caolin Blade, 8 Sean O'Brien, 7 Jarrad Butler, 6 Eoin McKeon, 5 Quinn Roux, 4 Gavin Thornbury, 3 Finlay Bealham, 2 Tom McCartney (captain), 1 Denis Buckley.
Replacements: 16 Dave Heffernan, 17 Denis Coulson, 18 Dominic Robertson McCoy, 19 James Cannon, 20 Eoghan Masterson, 21 James Mitchell, 22 Craig Ronaldson, 23 Darragh Leader.
Edinburgh: 15 Blair Kinghorn, 14 Dougie Fife, 13 Mark Bennett, 12 Chris Dean, 11 Duhan van der Merwe, 10 Jaco van der Walt, 9 Nathan Fowles, 8 Bill Mata, 7 John Hardie, 6 Magnus Bradbury, 5 Grant Gilchrist (captain), 4 Ben Toolis, 3 Simon Berghan, 2 Neil Cochrane, 1 Darryl Marfo.
Replacements: 16 Cameron Fenton, 17 Jordan Lay, 18 WP Nel, 19 Lewis Carmichael, 20 Cornell du Preez, 21 Sean Kennedy, 22 Duncan Weir, 23 Phil Burleigh.
Referee: George Clancy (Ireland)
Assistant Referees: David Wilkinson, Shane Kierans (Ireland)
TMO: Kevin Beggs (Ireland)
Photo: Connacht Rugby