And the trump card " throwing Nick Rodda, who had starred in defence, forward " almost paid off as the Falcons took a three-point lead two minutes into time on.
But the Royals rallied in the dying stages to win 10.12 (72) to 9.14 (68) in a memorable derby at Leederville Oval on Sunday.
The Falcons' forward 50 looked noticeably more dangerous with the presence of the big-bodied Rodda in it.
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READ NOWThe 21-year-old swingman added an extra marking option and kicked a goal as the Falcons piled on the attacking pressure to close a gap that stretched to 25 points early in the last quarter.
But despite forward Michael Lourey putting the visitors in front with his third goal, dangerous West Coast-listed teenager Tom Lamb (four goals) emerged as the match winner with an athletic mark and goal at the 28-minute mark to hand East Perth a four-point victory.
Falcons key backman Marcus Adams was a pillar of strength, taking a match-high 13 marks and providing crucial rebound during West Perth's late comeback.
West Coast hard nut Patrick McGinnity made a case for inclusion in this weekend's crunch clash against Hawthorn, taking 30 possessions and seven tackles for the Royals.
Fine winter conditions and a typically spirited derby crowd of 2934 created an absorbing atmosphere for the closest Leederville-based contest between the sides since 2004.
That year, West Perth outdid the Royals by three points in round 21 after East Perth beat the Falcons by a point in round seven.
Sunday's clash revived a spark between the sides at the historical ground after recent big margins, including West Perth's 100-point demolition last year and East Perth's 47-point triumph in May.
The defeat means West Perth remains in second place only on percentage, having lost the game in hand they had on third-placed Peel, who had a bye on the weekend.
The Falcons face East Fremantle away on Saturday.