The wear and tear of constant competition is finally taking its toll on Sam Kerr's Chelsea, which lost its second game of the Women's Super League season after going down 1-0 to Reading.
Canadian international Deanne Rose scored the winning goal in just the fourth minute of the match, driving through Chelsea's sluggish midfield and finishing off a simple one-two with Emma Harries to put the rejuvenated Royals ahead.
The goal broke Chelsea's record of eight straight matches without conceding. Having played three times in the space of 10 days, including an FA Cup final and a Champions League group game, Chelsea looked fatigued and could not find a way to break down Reading's well-organised defence.
Matildas captain Sam Kerr started her third consecutive game for the Blues despite Chelsea boss Emma Hayes having former European Player of the Year Pernille Harder and Norway winger Guro Reiten on the bench.
The matches also came off the back of Kerr's international duties, playing both friendlies against the USA in late November in Sydney and Newcastle.
The league's Golden Boot leader had a handful of chances on goal, including a free header in the first half that went wide and a one-on-one with Reading keeper Grace Moloney, but was unable to find an equaliser thanks to the Royals' desperate defending.
It was also the first time in 59 games that Chelsea finished a WSL match without a goal, ending the longest scoring run in league history.
Chelsea remains in second place on the table but is now four points behind leaders Arsenal, who defeated winless Leicester 4-0 on Monday morning.
It was a much-needed display of dominance from the Gunners following a string of losses in other competitions, including the FA Cup final and Champions League.
Jordan Nobbs opened the scoring in the 22nd minute, while Netherlands striker Vivianne Miedema made it two just after the half-hour. Substitute Frida Maanum scored twice in the space of three minutes in the game's closing stages to keep Arsenal at the top of the ladder.
The Gunners remain the only unbeaten side in the competition, having scored 30 goals and conceded just three in nine games.
Matildas goalkeeper Lydia Williams started for Arsenal while Steph Catley made an appearance off the bench. Caitlin Foord was an unused substitute.
Elsewhere in the WSL, Australian striker Kyah Simon scored a penalty for Tottenham Hotspur in their 2-1 win over Emily Gielnik's Aston Villa.
Simon cancelled out Villa's opener, converting from the spot in the 29th minute after New Zealand international Ria Percival was tripped in the box.
Spurs took the lead just after the hour after striker Rachel Williams was given acres of space between Villa's back-line, slotting home an easy pass from Jessica Naz.
Tottenham now sits third on the WSL ladder, four points behind Chelsea and two points ahead of both Brighton and Manchester United, who faced one another on Sunday with United emerging 2-0 winners.
Elsewhere in the league, both Mackenzie Arnold and Tameka Yallop started for West Ham in their 1-1 draw with Everton on Monday morning, while Manchester City came from behind to secure a 3-2 win over struggling Birmingham City.
Matildas winger Hayley Raso assisted City's second goal, crossing in the ball for Lauren Hemp to head home. Alanna Kennedy also made her return to the starting line-up following a leg injury, playing the full 90 minutes as City moved into sixth spot.
