Gabriel Martinelli hat-trick fires Arsenal in FA Cup fourth round
Gabriel Martinelli scored a hat-trick as Premier League leaders Arsenal cruised into the fourth round of the FA Cup with a 4-1 defeat of Portsmouth on Sunday afternoon.

The Blues ended a five-match winless run with a convincing performance against the Addicks under new head coach Liam Rosenior.
Charlton began brightly in the first ten minutes of the match before Chelsea began taking control of the match with a barrage of attacks against the home side.
The visitors were rewarded for their relentless pressure in the fifth minute of additional time in the first half after Jorrel Hato found the net from a good Marc Giui assist.
Chelsea continued with their aggressive attack-minded approach in the second half, forcing Charlton into making fouls, with Tosin Adarabioyo extending the lead in the 49th minute after a Facundo Buonanotte free-kick.
However, Charlton managed to pull one back against the run of play through striker Miles Leaburn in the 57th minute, to give hope of a comeback.
Five minutes later Marc Giui extended the Blues lead with a clinical finish from inside the box, forcing the visitors to make a triple substitution shortly afterwards as they chased the game.
Chelsea dominated the match thereafter but had to wait until injury time to add to their goal tally, with Pedro Neto producing an emphatic finish (90+1) and Enzo Fernandez converting a penalty three minutes later.
"Delighted, a really good start," said Rosenior to Chelsea TV after the match.
"I was delighted with the attitude and the application of the players in terms of duels and the intensity and what happens in football when you apply yourselves in football because they are such good players.
"Some of the passages of play that we had were a joy to watch. It's just the start (we wanted), we have another huge game on Wednesday [Arsenal] that we need to prepare for, but for a first game, I couldn't ask for much more."
Meanwhile, Charlton manager Nathan Jones bemoaned poor defending from his team despite an encouraging performance at the start of the match.
“For long periods we were good,” said Jones to the club website.
"The game plan worked, we nullified them to certain things. The goal before half-time was a killer, but it was a good strike.
"We then got ourselves back into it, and then the third goal is the one I have sleepless nights over. It is stuff we have conceded from before; to concede from that, it was a non-learning and that for me is the biggest disappointment from tonight."
Chelsea now turn their attention to Wednesday's Carabao Cup clash against Arsenal at Stamford Bridge.