The Spaniard not only cleared Andre Agassi from contention this week, but is the only player to have beaten Muster in the Austrian's last 31 finals.
That victory came in five sets in Kitzbuhel last August, almost two months after Costa had lost to Muster in the quarter-finals of the French Open after leading by two sets to one.
Muster, who has already retained titles in Mexico City, Estoril and Barcelona, extended his current run of clay-court victories to 34 matches yesterday by defeating Cedric Pioline 6-3 6-3 in yesterday's semi-finals. The unseeded Frenchman, who was unable to complete his quarter-final until late on Friday because of rain delays, managed to break for 3-1 in the first set and 2-1 in the second set but was unable to quell Muster.
Costa, who has not previously advanced beyond the second round, defeated Marcelo Rios of Chile 6-3 4-6 6-3 in a fascinating duel between two maturing 20-year-old talents. Rios, the No 13 seed, outplayed the Australian Open champion, Boris Becker, in the third round.
Rios was Muster's last victim in a final, having managed to take a set off the Austrian before losing in four sets in Barcelona a week ago. Yesterday, the Chilean left-hander failed to make the most of his opportunities, converting only three of 11 break points, although Costa must take credit for raising his game at crucial moments.
Costa took a 4-0 lead in the opening set, leaving his opponent wondering why he was not at least level, having had two chances in the second game and another in the fourth.
Matters did not improve for Rios when Costa saved three more break points in the opening game of the second set, but the Chilean did finally break for 3-2. Costa then levelled to 4-4 before Rios showed his determination by recovering the break in the next game.
The final set underlined the difference between the players on the day. Rios created a chance in the opening game, Costa denying him with a smash. Rios made two more openings in the fifth game, only to net a backhand to lose the first and to be foxed by a Costa drop shot on the second.
Rios lost a further seven points. He slumped to 0-40 in the sixth game, and Costa pounced, trapping Rios into missing a backhand. The Spaniard required only one match point to secure his place in the final, serving out to love.Reuse content