Reading and Swansea will have to do it all again at the Vetch Field after Icelander Ivar Ingimarsson spared the Royals’ blushes with a late leveller in the FA Cup third round tie which finished 1-1.
The League Two Swans, who reached the fifth round last season, were within three minutes of springing a shock against the Championship promotion-chasers after Paul Connor had put them ahead.
The former Rochdale striker kept up his record of scoring in every round so far as he turned home a deflected Lee Trundle shot after 32 minutes.
But Reading launched an all-out onslaught after the interval and with time running out they finally gained their reward as Ingimarsson lashed home from a tight angle.
The Royals named new signing Les Ferdinand in the starting line-up after the former England striker joined until the end of the season on Thursday. Lloyd Owusu made way in attack, while captain Graeme Murty missed out through injury.
Swansea recalled midfielder Leon Britton at the expense of Roberto Martinez after the Spaniard failed to shake off a hamstring strain.
Kenny Jackett’s side made a purposeful start and wasted little time in signalling their intentions as Connor blasted wide with barely a minute gone.
But gradually the Royals got hold of the game, with Bobby Convey causing all sorts of problems.
The American midfielder fired in a shot from distance after nine minutes which had goalkeeper Willy Gueret scrambling across his line.
Then, a minute later, the same player curled in a vicious inswinging corner which Nicky Forster just failed to direct at goal.
Ferdinand was already displaying his renowned aerial presence and was just off target with a close-range header from another Convey cross.
But Swansea’s adventurous three-pronged attack always looked capable of springing a counter-attack, and midway through the half Adrian Forbes and Andy Gurney forced goalkeeper Marcus Hahnemann into quickfire saves.
Andy Robinson was next to try his luck with a header from Britton’s cross.
And with 13 minutes to the interval the Swans got their reward as Trundle’s shot was deflected into the path of Connor, who turned home from close range.
Reading were no doubt given a half-time rocket by boss Steve Coppell and they came out with slightly more direction to their play at the start of the second half.
Convey almost slipped in Nicky Shorey after 50 minutes, before an Andy Hughes effort just evaded the lunge of Ferdinand at the back post.
The Royals fans thought they had grabbed a leveller six minutes later when Convey’s corner was missed by goalkeeper Gueret, but Ibrahima Sonko’s header was hacked off the line by defender Izzy Iriekpen.
As Reading turned the screw, Owusu came off the bench for Ferdinand after 58 minutes.
It was Sonko, though, who was proving the biggest threat as he got free again at the back post just past the hour mark only to glance wide.
Swansea were clinging on for dear life and after 74 minutes Steve Sidwell’s right-footed effort forced Gueret into another save.
And Glen Little also smashed an effort past the post with the visitors’ defence backing off.
Then, just as it looked like the Royals’ profligacy was set to cost them dear, Ingimarsson picked up the ball in the right channel and unleashed a stunning 25-yard effort which flew into the corner.