LONDON (AFP) - Arsenal made Leeds pay for their profligacy with a host of wasted first-half chances to reach the FA Cup fourth round with a 1-0 victory on Monday (Jan 6) thanks to Reiss Nelson's winner.
Leeds will hope more regular visits to the Emirates are in store as they top the Championship and showed why by dominating the first 45 minutes.
However, Patrick Bamford struck the bar, while Arsenal stand-in goalkeeper Emiliano Martinez made smart saves to deny Jack Harrison and Ezgjan Alioski.
Arsenal improved markedly after the break and secured back-to-back wins for new manager Mikel Arteta when Nelson bundled home from close range 10 minutes into the second half.
Arteta made just four changes to the side that beat Manchester United 2-0 on New Year's Day to kickstart his reign, although captain Pierre-Emerick Aubameyang missed out through illness.
But the Gunners looked more like the lacklustre outfit that preceded Arteta's arrival this season in the early stages as Leeds stroked the ball around confidently.
On-loan Manchester City winger Harrison twice stung the palms of Martinez either side of Bamford's strike coming back off the woodwork.
Alioski then forced the best save of all from the Argentine as he met a teasing Harrison cross at the back post.
Arteta's half-time team talk roused a response from Arsenal as Alexandre Lacazette also hit the crossbar from a free-kick.
Lacazette was captain for the night in Aubameyang's absence and led from the front after the break as he also had a hand in the winner.
The Frenchman was played in by Nicolas Pepe and his deflected cross found its way to Nelson to convert just his second Arsenal goal.
Nelson was then replaced by another talented youngster in Gabriel Martinelli, who came closest to adding to Arsenal's lead with a low shot that was well saved by Illan Meslier.
However, one goal was enough to secure the Gunners a fourth round trip to Bournemouth.