Chloe Kelly's late goal sealed an important win for Manchester City as they returned to the top of the Barclays FA Women's Super League table.
The 1-0 victory against Reading was an 11th consecutive success for Gareth Taylor's team, who leapfrogged Chelsea ahead of their game with Aston Villa on Sunday.
Lauren Hemp saw an effort strike a post and Weir put a golden chance over the crossbar with 10 minutes remaining, as it looked like the Royals would survive and earn a draw.
However, Kelly made the breakthrough after 87 minutes, finding the back of the net after Hemp had skipped past several Reading defenders to set her up.
Manchester United's first-ever appearance at Old Trafford proved a successful one as they won 2-0 against struggling West Ham.
James struck four minutes after the break when she glanced home a header, before Press slotted home six minutes later after latching on to Jackie Groenen's through-ball.
The visitors finished the match with 10 players after Laura Vetterlein was sent off after being shown a second yellow card in the 77th minute.
With United winning, the pressure was on Arsenal to respond in the race for Champions League football and they obliged with a 3-0 victory against north London rivals Tottenham.
McCabe settled the derby just after the hour when she pounced on a loose pass and found the bottom corner of the net.