Source: Elopement Technique Gains a Trick 
The elopement play is a technique in which declarer “runs away” with an extra trump trick. Opportunities for this are fairly common but often missed because declarer fails to reduce his trump length early on. It is necessary to ruff in the hand with longer trumps, a practice that goes against the grain of routine play.
On today’s deal a straightforward auction led to four spades. South’s invitational bid of three spades looks a bit sketchy but is correct on a point-count basis. If you don’t like it, remember that bridge is a bidder’s game; bold bids are rewarded far more often than discreet passes.
Contract: 4
Lead: Q
Declarer’s only real hope is an elopement play. He must try to win all five of his trumps, which means he must seek ruffs in his hand at every opportunity. The proper play is to win the club ace and lead the singleton diamond. Assume East wins with the queen and returns a heart (nothing matters) which South wins. Lead a spade to the king and ruff a diamond; lead a spade to the ace and ruff another diamond.
At this point declarer has one trump in each hand, and his goal is to win them both. Cash the club king and the other top heart (not essential), ruff a club in dummy, and lead a diamond. East has to play before you: If he ruffs, you will discard and your last trump will be high; if he discards, you will ruff to win your 10th trick immediately.
Of course, the elopement will not always succeed (teenage lovers take note). If the cards lay unfavorably, an opponent might be able to overruff and spoil your party. But here it cost nothing to try, since failure was inevitable otherwise.