Question on a play

[The_Missile]

[2-table tournament, hero is chip-leader at his table, UTG is short stack]
[Each chip is of equal value, blinds are at 2-4]

Hero is dealt 6d 8h in the big blind:
UTG calls, UTG+1 folds, button calls, SB folds, Hero raises to 8, UTG calls, button folds, SB folds.

Flop: 5 7 9 rainbow
Hero checks, UTG checks

Turn: J hearts (rainbow, no flush draw possible)
Hero checks, UTG bets 4, Hero calls

River: K
Hero checks, UTG bets 4, Hero moves all-in, UTG folds


Did I slow-play my straight properly? Should I have bet out the flop and/or turn? Now, the person I check-raised is very tight and I think he had top pair, but should I have bet the flop or turn to extract more chips having flopped the straight?