The 1959 Candidates Tournament, which started in September at Bled (then Yugoslavia, now Slovenia), was Fischer's third event featuring Soviet opposition. In August 1958 he had drawn against four Soviet opponents at the Portoroz Interzonal, and in May 1959 he had drawn with Tal and beaten Keres at Zurich. At Bled, Fischer, 16 years old, again faced Keres, 43, in the first round of the grueling eight player, 28 round event.
The photo below is from that first round game. Fischer has just played 9...Nbd7, and Keres is about to play 10.Be2, a move which Fischer called an 'innovation' and 'dubious', and which Kasparov assigned '!?'.
Source: Russians versus Fischer (p.29)
Mikenas explained the innovation (also in 'Russians versus Fischer'):
Before the tournament, on a fishing trip, Keres and I hit on an interesting variation in the Sicilian Defense, involving a Queen sacrifice. To celebrate our success, it was against Fischer that we decided to do our 'fishing' in these uncharted waters. The 'fish' went for the bait.
See Keres - Fischer, CT 1959 for my introduction to the game, including a link to Chessgames.com. Fischer included four games against Keres in 60 Memorable Games: the Zurich game (last discussed in Fischer Overlooks a Theoretical Draw), the current game, and two games from the 1962 Candidates Tournament.