Hibernian remain top of the SWPL after a thumping 4-0 win over Rangers at Ainslie Park.
Rangers had started the season unbeaten, but Lia Tweedie grabbed a hat-trick in a one-sided win for the Edinburgh side.
Glasgow City are just a point behind Hibs after they hammered Forfar Farmington 7-0.
Spartans beat Stirling University, but Celtic fell away from the top two after they were held at home by Motherwell.
Wake up call for Old Firm
Both Rangers and Celtic have both enjoyed encouraging starts to the season.
But weekend results have left both in danger of falling away from mounting a serious title challenge.
"It is definitely not a reflection of what we can do on the pitch," midfielder Jade Gallon told the Rangers website after the defeat by Hibs. "We feel as a group that we can perform a lot better.
"Obviously Hibs did well to put us under pressure, but we can do better with our problem solving. We should be able to deal with these situations on the pitch and that is something that we need to improve on."
City won't stop scoring
Glasgow City now have 28 goals in four games after a 7-0 win away to Forfar Farmington.
They led just 1-0 at half-time, but turned up the heat on their hosts in the second half and at the moment look unstoppable as they chase a 13th consecutive title.
"We just pulled it together as a team," hat-trick hero Clare Shine told Glasgow City TV. "We had such a bad first half we had to pull something out of the bag.
"Playing with the girls is brilliant. I've been in the right place at the right time. It could have been more."
Hutchison Vale won't stop conceding
In SWPL2, the top three all failed to win, allowing Kilmarnock to move from fourth to level on points with leaders Hearts after they beat Glasgow Girls 2-0.
The Jambos drew at home to St Johnstone, while Dundee United lost their first game of the season away to Partick Thistle.
But Hutchison Vale's woes continued, with a 12-0 defeat to Hamilton Academical meaning they have now conceded an alarming 34 goals in three games.