One of the most elegant and clever design decisions in Dominion, present from the very beginning with just the base set, is that victory cards are bad. Fundamentally, when players buy victory cards, they damage their deck, which slows them down so that the opponent(s) can catch up. Too many games neglect putting in a balancing mechanism like that, so when a player starts winning, they accelerate (I'm looking at you, Catan.) It takes careful and deliberate planning to get around that mechanism in Dominion, which is part of what makes engine-building so rewarding.
While I love Dominion and prefer it to Catan, Catan has two mechanisms that slow down a powerful player:
A: The robber. In a 4P game the robber should be on the most powerful player's space 75% of the time (and, if the powerful player buys development cards to mitigate the robber, these are resources he could be using to build cities - if he can do both, you're screwed either way).
B: Trade embargoes. Basically when a player begins to get powerful, every other player should refuse to trade with him or her. Let them deal with the bank or ports.
These are nowhere near as elegant as Dominion, but I've definitely played games with worse runaway leader problems (Acquire comes to mind immediately). Catan's issue is more a runaway loser problem - if you get blocked off early or players place their initial settlements in a way you don't anticipate, you usually have almost no chance of winning.