The Western Bulldogs leapfrogged Melbourne into top spot on the AFL ladder but lost key defender Alex Keath to a hamstring injury in the process of their gritty 20-point win.

Keath was substituted out of the game before quarter-time as Marcus Bontempelli, Jack Macrae and a hard-working midfield steered the Bulldogs to a 13.7 (85) to 9.11 (65) victory at the MCG on Saturday night.

Bontempelli kicked two of the Dogs' five goals from forward-50 stoppages, which proved decisive in a tight game that they led by just four points mid-way through the last quarter.

The Bulldogs played the final term a man down after losing Ed Richards to concussion, but now sit two points clear of Melbourne in first place and boast the competition's best percentage.

"Losing Keathy made it a little bit difficult and stretched us a little bit ... but the boys really worked their way through the game and fatigue extremely well," Bulldogs coach Luke Beveridge said.

"It's a win full of heart in the end when you consider that Melbourne got within a goal and we steadied ourselves and showed some pretty good composure. I'm really proud of the boys."

Bontempelli had 31 disposals and combined with Macrae (38 disposals) to generate 19 clearances, while Caleb Daniel (34 disposals), Lachie Hunter (26) and Tom Liberatore (27) were also strong contributors.

Josh Bruce, Aaron Naughton and Mitch Hannan kicked two goals each and No.1 draft pick Jamarra Ugle-Hagan, who had been quiet all night, booted a crucial major from a set shot in the final term.

With Keath out of action, versatile tall Josh Schache stepped up to play an important role in defence, having been recalled for his second game of the season.

Clayton Oliver had 38 disposals, 25 contested possessions, eight clearances and eight inside-50s for the Demons, with midfield partner Christian Petracca (31 disposals) also in the thick of the action.

Max Gawn (57 hitouts) got first hands on the ball in his ruck battle with Tim English (14), but the Bulldogs got on top at ground level, winning clearances 49-41.

Melbourne forwards Ben Brown, Bayley Fritsch and Kysaiah Pickett kicked two goals each, but missed set shots cost the Demons momentum at crucial times.

If Geelong beat Richmond on Sunday, the Demons could slip as low as third by the end of the round, having won just two and drawn one of their last six games.

"All night we were in the game, some of our method at times was really strong and we got our looks," Melbourne coach Simon Goodwin said.

"But it's full credit to the Bulldogs, they were that little bit more efficient inside forward-50 and they scored at those stoppages.

"Our belief hasn't wavered. We still feel really confident in our game, but tonight we just got beaten in the efficiency side of things."

A lopsided free kick count went the Bulldogs' way (25-11).