January signing Leandro Trossard arrowed a stunning strike into the net midway through the first half, but the Belgian was denied his second goal for Arsenal after VAR ruled that Ben White had fouled goalkeeper Danny Ward in the build-up.

It took the dominant visitors until the first minute of the second half to break the deadlock when Martinelli raced on to a Trossard pass and stroked home what proved to be the winner.

The hosts did not look like getting back into the contest, with Arsenal seeing out the win that stretched their lead over Manchester City, who were playing at Bournemouth later on Saturday. Leicester stay 14th, three points clear of the relegation zone.

"We create more belief in and around the club. I had full faith that the players could do it (come back from recent defeats)," Arsenal coach Mikel Arteta said.

"It was about coming back to some basics, some details that in the past had taken games away from us. Not conceding, giving chances away, is so important in this league."

With the title race twisting and turning each week, Arsenal travelled north to Leicester fully anticipating a tough match against a side who thrashed Tottenham Hotspur 4-1 in their previous home game.

The hosts, without the influential James Maddison in midfield due to illness, never really got going, however, and failed to muster a shot on target in the match.

The visitors did not have to overly exert themselves to get the job done. Trossard was unlucky in the first half -- he will not hit many better strikes all season.

Martinelli's finish was equally impressive on the run. No Arsenal player has more league goals than the Brazilian this season.

The result could have been more comfortable, with Arsenal having the ball in the net again only for it to be ruled out for offside, but they had no trouble seeing out the victory to keep them on course for a first league title in 19 years.

Arsenal have now won 10 of their 13 away league games this season, one more than in the whole of last term. It is the fastest they have reached 10 away wins in any league campaign.

"They were clearly better than us," Leicester coach Brendan Rodgers said. "We were too passive when we had the ball, we weren't quick enough with it.

"When we got to the final third we could not find that last pass. They are at the top of the league for a reason, and I thought they showed that."