Arsenal avoided an upset and booked a place in the semi-finals of the FA Cup on Sunday (AEDT), but defeating fifth-tier Lincoln City 5-0 at Emirates Stadium is unlikely to ease the intense scrutiny bearing down on manager Arsene Wenger.

Strikes from Theo Walcott, Olivier Giroud, Alexis Sanchez, Aaron Ramsey and Luke Waterfall's own goal sealed the victory, but more protests prior to the game called for the departure of the veteran manager, who is out of contract at the end of the season and under pressure to walk away having failed to win the Premier League since 2003-2004.

A humiliating 5-1 loss to Bayern Munich in the UEFA Champions League in midweek, which sealed a catastrophic 10-2 aggregate exit at the Round of 16 stage for a seventh successive season, could yet prove too great an embarrassment for Wenger to bear when he comes to determine his future.

Ending lowly Lincoln's fairy-tale run in north London will do little to assuage the concerns of Gunners supporters demanding action from the club's board, which has staunchly backed the 67-year-old throughout a long spell of capturing minimal silverware.

Wenger has only delivered three FA Cups since 2005 and he could still lift the trophy again in May, Arsenal joining Manchester City in the last four, with Tottenham Hitspur at home to Millwall on Monday (AEDT) and Manchester United visiting Chelsea a day later.

But it is in the league where Wenger's future is likely to be determined, with anything less than a top-four finish and UEFA Champions League qualification expected to result in the departure of English football's longest-serving active manager.  

Arsenal overcame a somewhat nervy start to control the contest as expected, although it took until the 14th minute for its first clear-cut opportunity to arrive, Lincoln goalkeeper Paul Farman making a strong save low down to his left to keep out Walcott's well-struck volley.

Wenger was forced to make a change in the 27th minute, Alex Oxlade-Chamberlain limping off with a suspected hamstring injury and being replaced by Mesut Ozil. 

Two minutes later, Lincoln carved out its first good chance. Played in by powerful centre-forward Matt Rhead, Nathan Arnold advanced into the area down the right, cut inside Laurent Koscielny and forced Petr Cech to turn the ball behind for a corner.  

The away team's resistance was finally broken in stoppage-time at the end of the first half, when Kieran Gibbs teed up Walcott just inside the box and the forward's deflected shot beat Farman.

Arsenal continued to dominate early in the second half and made it 2-0 in the 53rd minute, Hector Bellerin playing a neat one-two with Sanchez before cutting the ball back for Giroud, who made up for a clumsy attempt moments earlier by stroking the ball home confidently.  

Waterfall allowed the floodgates to open when he inadvertently steered a Gibbs pass into the back of his own net two minutes before the hour mark.

Sanchez then curled home a stylish fourth in the 72nd minute after skipping impudently past a heavy attempted challenge by Alex Woodyard.

The Chile international was instrumental in making it 5-0 three minutes later, the former Barcelona man bamboozling the Lincoln defence before finding Ramsey at the back post, where the Wales midfielder walked the ball around Farman and into the back of the net.

Next up for Arsenal, which nearly made it six when Sanchez smashed a free-kick against the bar in the 85th minute, is a trip to face West Bromwich Albion in the Premier League, as the fifth-placed Gunners seek to get their top-four challenge back on track.