Match ends, Arsenal 2, Hull City 0.
Arsenal began their defence of the FA Cup with a hard-fought win as Hull City failed to gain a measure of revenge for defeat in last year's final.
Per Mertesacker rose above the Hull defence to powerfully head in the opener from Alexis Sanchez's corner.
Arsenal controlled the first half and almost doubled their lead when Hull's Paul McShane cleared off the line.
Hull grew in confidence after half-time but Sanchez's sharp turn and calm finish inside 18 yards sealed victory.
The Chile forward has become Arsenal's talisman since his £35m summer move from Barcelona and another moment of quality eased any lingering fears of Hull snatching a late draw at the Emirates.
In truth, the Tigers rarely looked capable of avenging their dramatic 3-2 defeat at Wembley last May and this third-round tie failed to match the fever and tension of last season's showpiece.
Arsenal controlled 65% of the possession in the first half, but failed to transform their dominance into a comfortable lead against injury-hit Hull.
|Teams to have retained the FA Cup|
|The Wanderers (1871-72, 1872-73)|
|Blackburn Rovers (1889-90, 1890-91)|
|Newcastle United (1950-51, 1951-52)|
|Tottenham Hotspur (1960-61, 1961-62)|
|Tottenham Hotspur (1980-81, 1981-82)|
|Arsenal (2001-02, 2002-03)|
|Chelsea (2008-09, 2009-10)|
Tigers boss Steve Bruce was left with only 18 first-team players available, but still managed to make 10 changes from the side which beat Everton on New Year's Day.
Hull are fighting for top-flight survival and Bruce decided to freshen up his squad as he prioritises forthcoming Premier League matches against West Brom and West Ham.
His changed team provided plenty of endeavour but they lacked the guile needed to hurt an Arsenal side which suffered their first defeat in six matches at Southampton on New Year's Day.
Hull raced into a 2-0 lead inside eight minutes when they met at Wembley and, although the visitors made another high-tempo start, Arsenal were more defensively alert on this occasion.
And once skipper Mertesacker escaped Hull counterpart Curtis Davies to nod in the opener, the Gunners never looked in danger of suffering a second home FA Cup defeat in 39 matches.
|Watch every FA Cup goal|
|Click here to find highlights from every game|
Arsene Wenger's side did lose some rhythm in the first part of the second half as Hull pressed their opponents higher up the pitch. But they failed to seriously stretch Gunners keeper David Ospina.
England forward Theo Walcott, 24, played 75 minutes on his first Gunners start for exactly a year as he continues to make his comeback from a serious knee injury and showed brief flashes of his pacy threat.
A Santi Cazorla pass allowed Sanchez to clinically fire in as Arsenal continue their bid to become only the eighth club to retain the FA Cup.
Hull City manager Steve Bruce:
"If we're going to be honest Arsenal deserved to win. We just needed to stay in there but unfortunately, at the top end of the pitch, we were unable to create anything.
"The disappointing thing for me is that the first goal is the first we've conceded from a corner this season. Mertesacker is huge - we should be doing better than that. We battled on valiantly but we weren't quite good enough.
"I know most teams get injuries but we can't carry six or seven missing - that's what we were doing today. We were down to the bare bones but there are no excuses, the better team won."
- 34CoquelinBooked at 87mins
- 14WalcottSubstituted forOxlade-Chamberlainat 76'minutes
- 28CampbellSubstituted forMaitland-Nilesat 90+1'minutes
- 17SánchezBooked at 76minsSubstituted forAkpomat 84'minutes
- 15McShaneBooked at 45mins
- 6DaviesBooked at 85mins
- 20SagboSubstituted forHernándezat 67'minutes
- 24AlukoSubstituted forEl Mohamadyat 62'minutes
- 27El Mohamady
- Robert Madley
- Shots on Target
Second Half ends, Arsenal 2, Hull City 0.
Attempt missed. Abel Hernández (Hull City) header from the right side of the box misses to the right. Assisted by Ahmed Elmohamady with a cross.
Substitution, Arsenal. Ainsley Maitland-Niles replaces Joel Campbell.
Attempt missed. Tom Ince (Hull City) right footed shot from outside the box is too high.
Delay over. They are ready to continue.
Delay in match Alex Oxlade-Chamberlain (Arsenal) because of an injury.
Attempt saved. Tom Huddlestone (Hull City) right footed shot from outside the box is saved in the centre of the goal. Assisted by Stephen Quinn.
Francis Coquelin (Arsenal) is shown the yellow card for a bad foul.
Foul by Francis Coquelin (Arsenal).
Harry Maguire (Hull City) wins a free kick in the attacking half.
Attempt missed. Alex Oxlade-Chamberlain (Arsenal) right footed shot from outside the box is high and wide to the right. Assisted by Per Mertesacker.
Curtis Davies (Hull City) is shown the yellow card for a bad foul.
Alex Oxlade-Chamberlain (Arsenal) wins a free kick on the right wing.
Foul by Curtis Davies (Hull City).
Substitution, Arsenal. Chuba Akpom replaces Alexis Sánchez.
Goal! Arsenal 2, Hull City 0. Alexis Sánchez (Arsenal) right footed shot from the centre of the box to the bottom right corner. Assisted by Santiago Cazorla.
Attempt missed. Abel Hernández (Hull City) left footed shot from a difficult angle and long range on the left is high and wide to the left. Assisted by Stephen Quinn.
Attempt blocked. Joel Campbell (Arsenal) left footed shot from outside the box is blocked.
Substitution, Arsenal. Alex Oxlade-Chamberlain replaces Theo Walcott.