Jack Wilshere lit up the FA Cup replay between Arsenal and Swansea, while Wayne Rooney made a goalscoring return for Manchester United in another exciting night of Cup action.
Wilshere was the man of the moment for Arsenal, who scored a late goal via the Arsenal midfielder to come out with a thoroughly deserved 1-0 victory and book themselves a place in the fourth round, where they will meet Championship side Brighton & Hove Albion.
Rooney made his comeback from injury in splendid style, scoring in the ninth minute for United.
Another returning player Anderson, played a brilliant through ball to Javier Hernandez, who in turn played in Rooney to tap in from close range.
The England forward, however, missed a panelty with a little over ten minutes remaining, after Ryan Giggs had forced a handball off West Ham's Jordan Spence.
That miss did not prove to be too costly, though, with West Ham, despite giving it a good go to try and find the equalizer, not able to find a way through.
At the Emirates, Arsenal began on the front foot, immediately quickening their pace of the game while going forward.
Arsene Wenger chose to play Olivier Giroud up front, with Theo Walcott going on the right, and Jack Wilshere playing in a more advanced position with Santi Cazorla on the left.
The tactics seemed to work for the first ten minutes or so, with Giroud coming close on a couple of occasions.
The first chance fell to the French international off a Walcott, cross, but his near post header did not trouble goalkeeper Michel Vorm. Then the striker had another opportunity, but struck his shot wide with his weaker right foot.
Swansea slowly grew into the game, keeping possession really nicely, with a couple of times turning that possession into chances; Nathan Dyer went close twice, but was denied by good tackles from Thomas Vermaelen.
The Arsenal skipper then fired a freekick into the wall with the resulting corner seeing Francis Coquelin, Arsenal's defensive midfielder in the game, striking a tame effort straight at Vorm.
Swansea should have gone ahead soon after, but former Arsenal player Kyle Bartley headed a nice Wayne Routledge cross onto the crossbar; incidentally the defender had also struck the woodwork in the third round game at the Liberty Stadium, which finished 2-2.
Wilshere was enjoying himself, playing in a more advanced position, and looked dangerous every time he decided to make a direct run down the middle. One such run resulted in Walcott receiving a glorious opportunity, but the Arsenal forward could not find a way past Vorm.
Vermaelen then really should have put Arsenal ahead on the stroke of halftime. Per Mertesacker deflected the ball towards Vermaelen's path, off a Walcott corner, with the Belgian seeing his instinctive strike saved by Vorm with his feet.
The second half was all Arsenal, with Wilshere showing his talent to the entire world. The Arsenal midfielder was the chief orchestrator of the Gunners symphony, as the home side produced wave after wave of attacks.
Walcott had the first chance of the second period, with the 23-year-old missing the target after being out through clear on goal by Abou Diaby.
Cazorla then struck wide off a long-range shot, with Giroud missing the target with a header. Wilshere forced a save from Vorm, who made some outstanding saves in the second half, with Walcott seeing his follow up strike Danny Graham on the line, with suspicions of a handball.
Leon Britton then amazingly cleared off the line for Swansea for the second time in seconds, before Walcott fired wide off a Wilshere through ball.
Everything from Arsenal was coming via Wilshere, with the 21-year-old deciding to take matters into his own hands, forcing a wonderful save from Vorm. Giroud, soon after, saw his shot cleared off the line yet again, this time by Dwight Tiendalli.
Just when it looked like Arsenal were not going to break through, with Swansea hanging on for dear life and trying to force extra time, Arsene Wenger's side struck the winner.
Cazorla played a nice ball to Giroud, who brilliantly flicked it to the oncoming Wilshere to strike it first time into the back of the net from 20 yards in the 86th minute.
Arsenal again threatened to increase the lead a couple of times, but eventually settled for the most emphatic of 1-0 wins you will ever see.