Auction: (1♦)-P-(1♥)-2♣-(3♦)-3♠
At every table where the hand was played in a spade contract, the play to the first few tricks was the same, ruff second diamond, cash ♠A, dropping the K, and after that is where I apparently went wrong. I reasoned that if I lead the ♠ 9 back to my hand like all the other spade declarers did, and then played a heart toward the KQ, I would have no way back to my hand if the heart was allowed to hold. Instead, I played the ♥K off dummy, won by West with the A. West returned the ♣7. Rather than risk the finesse, I tried what turned out to be a hopeless squeeze. I want up A, played the ♠9 to my hand and ran the ♠'s coming down to this:
Scoring: IMP
5 ♠ South. Opening lead ♦7. East wins and returns a ♦. How do you proceed?
5 ♠ South. Opening lead ♦7. East wins and returns a ♦. How do you proceed?
Note that at least one pair that made 5 just lost a club to East and East did not return a heart. I think in another case West went up A on the first lead of ♥ to dummy, but I can't swear to that. So, the question(s): with best defence, can it be made? Was my line totally terrible, especially given the bidding?
*Comments about the bidding are not unwelcome and will most likely be entertaining

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5 ♠ South. Opening lead ♦7. East wins and returns a ♦. How do you proceed?