The GIANTS learned a lesson about "staying in the game for longer" on Saturday after a seven-minute lapse against St Kilda cost the young team an opportunity to notch its first win in Melbourne.    

After building a 20-point lead in the third term, the GIANTS took their foot off the pedal and conceded four straight goals to the Saints, who stole a five-point lead and all the momentum heading into the final quarter.

GWS coach Leon Cameron said his team's inability to take chances was the difference after the GIANTS kicked 4.7 in the second half to lose by seven points.

"We had an opportunity for the first part of the third quarter and didn't take it – they really took their opportunities," Cameron said.

"They kicked four or five goals in seven or eight minutes (in the third quarter).

"(Nick) Riewoldt, Lenny Hayes, Leigh Montagna, their experienced players really stepped up … David Armitage was terrific.

"We've got to learn from that. Today we learned a lesson about staying in the game for longer."

With key forwards Jeremy Cameron and Jon Patton combining for just one goal, the Giants relied on ruckman Jonathan Giles (four goals) and Devon Smith, who kicked a career-high five, to keep them in the game.

"Our key forwards were probably a little bit down – Jonny Patton and Jeremy Cameron struggled a little bit to get into the game," Cameron said.

"But I didn't think our ball movement was great at times. We just lacked a little bit of polish to finish off at times.

"We talked after the game about just doing the fundamentals of the game really well, especially when you're fatigued, under pressure.

"Our basic fundamentals of hitting a target, first-give hands, kicking long when you have to or hitting up someone, that probably disappeared when we were fatigued."

Ruck recruit Shane Mumford was outstanding for the GIANTS, finishing with 46 hit-outs and 18 possessions (15 contested).

Defender Nick Haynes, meanwhile, spent four quarters opposed to Riewoldt and would have benefited from the experience.  

"We thought he held his own for periods of the game … it's very hard to keep such a good player down," Cameron said.

"They took 15 marks inside 50 and we've been trying to get that down to about 10.

"It's a fantastic opportunity for Nick Haynes to play on one of the best players in the competition."