Port know start crucial against AFL's Cats Port Adelaide risk getting smashed by Geelong in Friday night's AFL semi-final if they think they can rely on their comeback capacity, captain Travis Boak admits. Boak says the Power's increased fitness and ability to over-run teams late in games has been a big weapon this season. On four occasions during the regular season, they notched wins after trailing at the last change, including against reigning premiers Sydney and arch-rivals Adelaide. Their staying power was again on display in last Saturday night's elimination final win over Collingwood, when they turned an eight-point three-quarter-time advantage into an emphatic 24-point triumph. But Boak noted they didn't get the defensive side of their game functioning as well as they would have liked in the first half, were well beaten in the tackle count and were outpointed for contested possessions. He said Port's fast finishing would count for little if they're not on song early against the Cats. "It's given us great belief, we've done it a fair bit in the last quarter but we need to make sure we're on right from the start," Boak told reporters in Adelaide on Monday. If we give Geelong a sniff they're going to smash us. It's going to be pretty hot early. Boak speaks from experience, with Geelong having dominated the Power early in their two previous games this season, kicking seven goals to none in the first quarter in round nine and six goals to one by the first change in round 20. Boak said the big positive from the Collingwood clash was that Power players, many of them young and in their first final, were brave enough to play their own style, move the ball fast and take the Magpies on. It was exciting to see the likes of Sammy Colquhoun in his first year take the game on, Chad Wingard, Ollie Wines played a ripper game. These sort of guys who have just come into the system," he said. They'll again take a no-fear, nothing-to-lose attitude to the MCG. But Boak stressed that didn't mean they were satisfied with what they've achieved or would be content if their season ends on Friday night. The skipper, who the Cats tried hard to lure to Simonds Stadium last off-season, is looking to have a bigger personal impact after being kept to just 14 touches by Collingwood's Brent Macaffer in the elimination final.