BASEL, Switzerland (AP) -- Swiss underdog FC Basel pulled off another Champions League shock Wednesday, stunning German giant Bayern Munich 1-0 in the first leg of their last-16 match.

Substitute Valentin Stocker struck in the 86th minute, firing his shot through the legs of goalkeeper Manuel Neuer.

Basel was denied by the frame of Bayern's goal twice in an exhilarating first half, and showed the same fearlessness that helped oust Manchester United in the group stage at its noisy St. Jakob Park stadium.

Still, Basel relied on an exceptional performance from goalkeeper Yann Sommer, who made a string of fine saves.

"I had a bit of luck on my side but I made the right decisions,'' Sommer said. "We have beaten possibly two of the best teams in the world.''

Sommer excelled in blocking shots from Franck Ribery twice in the opening 11 minutes, and Mario Gomez who ran clear in the 72nd.

Basel coach Heiko Vogel hailed his players' "talent and quality and belief.''

"It's very simple - we have an unbelievable will to win and a great understanding among the team,'' said the 36-year-old Vogel, once a Bayern youth coach who took charge at Basel just four months ago.

The return match is March 13 in Munich - where the final will also be staged in May, heaping extra pressure on four-time European champion Bayern to avoid a shock elimination.

Bayern coach Jupp Heynckes acknowledged that "the alarm bells are going to be ringing'' after the loss followed a relatively poor run of Bundesliga results.

"We're not in an ideal position for the return game. We need to start winning, that's decisive,'' Heynckes said.

Pre-match talk had centered on Basel star Xherdan Shaqiri, who will join Bayern next season after the clubs agreed a reported ?11.6 million ($15.3 million) transfer this month.

Shaqiri's more illustrious future teammates made an assured start, forcing Sommer into action twice in the opening minutes.

Gomez was forced wide by Sommer's alertness and lost his chance, before Ribery was denied at close range following Arjen Robben's deft pass.

Shaqiri had a clear sight of goal in the 8th but took a second touch from Markus Steinhoefer's cross and lost possession.

Ribery was denied again by Sommer's diving save in the 11th, as the German visitors seemed poised to dominate.

"We had two huge chances early on,'' Heynckes said. "It's important to take those chances so you can be relaxed approaching the rest of the game.''

The momentum turned in a frantic three-minute spell sparked by another Steinhoefer cross from Basel's right wing. Marco Streller's near-post flick forced a tipped reaction save by Neuer.

The Germany international did even better to push defender Aleksandar Dragovic's header against the post, and the ball rebounded back along the goalline before Holger Badstuber cleared the danger.

Basel was denied by the frame again in the 19th when Alex Frei swept a left-footed shot from 10 meters (yards) against the crossbar.

Seconds later, Neuer completed a quick hat trick of saves when Shaqiri shot from distance.

Bayern missed the steady presence of injured midfielder Bastian Schweinsteiger, though teenager David Alaba advanced in the 29th to shoot and force Sommer to save high to his right. The Switzerland stopper was soon called on again to block shots from Ribery and Gomez.

An exciting half, played in excellent spirit, ended soon after Bayern captain Philipp Lahm persuaded Italian referee Nicola Rizzoli not to award his side a corner kick after a tangle in the Basel penalty area.

Both coaches succeeded in tightening their defensive plans during the break, though Bayern maintained the majority of possession.

Sommer continued to impress, saving Gomez's overhead kick and Lahm's 20-meter (20-yard) shot after cutting in from the left.

As Bayern pressed again, Gomez darted into the box but Sommer spread himself wide to block the shot, then bravely punched the loose ball clear under a heavy challenge from substitute Thomas Mueller, who was cautioned.

Though Shaqiri was replaced in the 83rd by Jacques Zoua, Basel came on strong at the end and Zoua found Stocker to score a memorable winning goal.

Former Bayern great Franz Beckenbauer, who captained the team in its 1970s heyday, said Basel deserved to win "for playing the way they did.''

"It's a disappointment, but there's still the chance of turning it around,'' Beckenbauer told German TV station Sat1. "Bayern can beat this team in Munich 2-0 or 3-0.''

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