The Sphinx, who had Jackson Downie sent off, thought they had progressed in normal time before Simon Williams' last-minute equaliser for Lye, but Downes popped up in the first half of extra time to seal a spot in the preliminary round away to Rugby Town.
Coventry Sphinx 2-1 Lye Town
The Emirates FA Cup
Extra preliminary round replay
Monday 17 August 2015
Sphinx Drive
Winning clubs receive £1,500
Lye have made a blistering start to their Midland Football League Premier Division campaign having won two from two, scoring nine goals in the process, but they found the going a bit tougher against their divisional rivals at Sphinx Drive.
Having drawn the first clash at Bromsgrove Sporting's Victoria Ground 2-2 on Saturday, the Flyers struggled to create any meaningful chances in a cagey first half which ended 0-0.
Sphinx – FA Vase quarter-finalists in the 2007-2008 season – took the lead on 69 minutes as Richard Blythe headed home Lewis McBride’s cross.
But after right-back Downie was shown a red card, Williams, who scored both of Lye's goals in the first game, ensured the replay would go the distance with a 90th-minute leveller to stun the home crowd.
However it was Downes, son of former Coventry Sphinx keeper Gavin, who proved to be the hero for the depleted hosts with a superb 35-yard lob in extra time.