Martha Thomas' ninth goal of the season fired Tottenham to a maiden victory over Arsenal in the Women's Super League.Jonas Eidevall's Arsenal entered this fixture eyeing an eighth consecutive league win, but the day belonged to his fellow Swedish coach Robert Vilahamn, who claimed a statement result at Tottenham Hotspur Stadium.Under the watchful eye of Spurs men's boss Ange Postecoglou and chairman Daniel Levy, Vilahamn's team held firm during a tight first half and produced a superb team move in the 58th minute, which was expertly finish by Thomas.The visitors pushed for a late response, but could not find a way through to hand Tottenham a 1-0 win and a first triumph over their rivals at the eighth time of asking in the WSL.The two rivals warmed up for this league fixture with an entertaining 3-3 draw in the Conti Cup on Wednesday, but chances were far and far between in the opening stages.It took until the 12th minute for the first opportunity of note when a Caitlin Foord effort deflected wide to earn Arsenal a corner.Eidevall's side produced a neat short corner routine and it should have resulted in the opener, but Alessia Russo inexplicably headed wide from four-yards.Spurs had shipped 11 goals in their last two WSL matches, which saw Vilahamn hand Barbora Votikova a first league start and the post came to her rescue soon after when Foord again cut inside and rifled a shot against the woodwork.Tottenham were forced to replace centre-back Luana Buhler minutes later before Arsenal had penalty appeals waved away after Beth Mead went down after contact from Ashleigh Neville.The hosts were able to regroup afterwards though and Celin Bizet posed questions of the visitors defence with two dangerous runs down the right.Arse