Turkey break Swiss hearts
Just as it seemed the co-hosts had done enough to stay alive in the competition, Arda broke clear on the left, cut inside and beat goalkeeper Diego Benaglio from the edge of the area with the help of a cruel deflection off the boot of centreback Patrick Muller.
It was harsh on the Swiss, who were left to count the cost of wasting the chances they had to kill off the Turks long before the dramatic denouement.
"It is a wonderful feeling," said delighted Turkey coach Fatih Terim. "The players needed this for their confidence and I congratulate them on their incredible effort."
Turkey can now join Group A leaders Portugal in the quarter-finals by beating the Czech Republic in their final game and Fatih added: "This win has given us a lot of confidence for the last game. Today is the begininng of the Euro for us.
"It was not easy, the conditions were difficult and Switzerland are a very strong team, playing at home. So was an important win."
Hakan Yakin, one of three players in the Swiss side with family roots in Turkey, had given Jakob Kuhn's side a first-half lead.
But the veteran playmaker also wasted two glorious chances to claim a second goal for his side, who were pegged back when substitute Semih Senturk headed in an equaliser just before the hour mark.
"It is hard to find the words to say how terribly disappointed we are," Hakan said. "The weather played a role, it was a bit of a lottery in the first half and in the end the luckier of the two sides won."
Swiss boss Jakob Kuhn described his squad's exit as "painful."
"The disappointment is huge of course but I can't criticise anyone. The team played as well as they could and they lost two matches in a rather unfortunate way. I'm not saying we were better but we had the chances to score a second goal."
Portugal's victory over the Czechs earlier in the evening had simplified matters for the Swiss, who kicked off knowing defeat would mean the end of their tournament.
Injury had taken its toll on both sides, with the co-hosts deprived of captain and leading goalscorer Alexander Frei and his usual strike partner, Marco Streller, with the result that Hakan was partnered in attack by the 19-year-old Eren Derdiyok.
Turkey were missing regular captain Emre Belozoglu and key defender Gokhan Zan for what was the first meeting between the two countries since their play-off for a place at the last FIFA World Cup ended in a mass brawl.
The pre-match suggestions that that was all water under the bridge was belied by the ferocity of the early exchanges but a torrential downpour drew the sting from the encounter.
It was the Swiss who adapted better to the water-logged surface, thanks largely to the marshalling of Gokhan Inler.
The midfielder was first to test Volkan Demirel's handling, with a skidding long-range effort, and it was his crossfield pass that gave Hakan the opportunity to force the Turkish goalkeeper into a smart save at his near post.
Volkan also did well to keep out Tranquillo Barnetta's free-kick before Arda struck the woodwork at the other end, although the Turkish midfielder knew little about it as Diego Benaglio's punched clearance from Nihat Kahveci's free-kick rebounded off his head and against the post.
With just over half an hour gone, the direct Swiss approach paid off. Philippe Senderos's punt landed in the Turkish box and with the sodden turf stopping the ball, Derdiyok was able to skip round the outrushing Volkan and square across the saturated goalmouth for Hakan to tap in at the back post.
Three minutes later, Hakan was guilty of the miss of the tournament after Valon Behrami's low cross from the right found him in an almost identical position. Astonishingly, the most technically gifted player on the pitch contrived to slice the ball wide from three yards out.
Such a flagrant miss was always like to prove costly and Turkey, who switched to a three-man forward line with the introduction of Semih at the break, capitalised on the let-off 11 minutes into the second half.
Nihat swung in a cross from the left and Semih rose unchallenged to head the ball past Benaglio from close range.
With seven minutes left, Hakan had another clear sight of goal but side-footed straight at Volkan and, with the hosts straining for the winner, it was Turkey who were to make their superior finishing count at the death.