LONDON, Nov 8 (Reuters) - Arsenal striker Alessia Russo struck late to snatch a 1-1 draw with Chelsea in the Women's Super League at the Emirates Stadium on Saturday, with the Gunners denied what would have been a vital victory due to two disallowed goals.

The result leaves table-toppers Chelsea, who are chasing a sixth straight league title, on 20 points after eight games, with Arsenal moving up to fourth on 15 points and ahead of Tottenham Hotspur on goal difference, but their North London rivals have a game in hand.

Desperate for a win that would catapult them back to the front of the pack, Arsenal went behind in the ninth minute when Chelsea's American striker Alyssa Thompson scored with a brilliant chipped finish.

Stina Blackstenius thought she had levelled for Arsenal in the 54th minute, blasting home the ball after a corner, but the goal was ruled out for handball. Television replays showed little evidence of any contact with the striker's hands or arms.

Arsenal finally managed to level in the 87th minute when Russo fired a first-time finish that Chelsea keeper Hannah Hampton could not keep out, and that set up a grandstand finish that offered even more controversy.

Arsenal substitute Frida Maanum thought she had won it with a cool chip past Hampton in the 90th minute but the flag went up for offside and, again, the goal was chalked off.

That decision prompted howls of protest from the Arsenal fans in the crowd of more than 50,000, and the final whistle saw another loud chorus of boos ring out around the ground.

In the other game of the day, Manchester United's ( MANU ) title push suffered a setback when they fell to their first defeat of the league season by losing 1-0 at home to Aston Villa. They remain third in the table on 17 points, with Villa sixth on 10 points.