RIOMAGGIORE, Italy (AP) - Denis Menchov took the overall lead from Danilo Di Luca at the Giro d’Italia on Thursday by winning the race’s key individual time trial, and dedicated the victory to injured teammate Pedro Horillo Munoz.

A Russian rider with the Rabobank team, Menchov clocked 1 hour, 34 minutes, 29 seconds over the highly technical 60.6-kilometer (37.6-mile) route along the coastal area known as Cinque Terre.

Horillo Munoz tumbled 60 meters (yards) off the side of the road in a high-speed descent on Saturday and is recovering from severe injuries at a hospital in Bergamo.

"He was very unlucky and I hope he bounces back soon," Menchov said of the Spaniard.

Di Luca finished sixth, 1 minute, 54 seconds behind Menchov, and dropped to second overall, 34 seconds behind.

"Today was one of the most decisive stages so far in this tour," said Menchov, who also won the race’s toughest uphill finish to Alpi di Siusi in stage 5. "It was an important step toward to trying win, but nothing is decided yet. There are still a lot of harder stages to come."

Levi Leipheimer of the United States placed second in the time trial, 20 seconds behind, and Stefano Garzelli of Italy was third, 1:03 back.

Lance Armstrong, Leipheimer’s teammate at Astana, was 13th, 2:26 behind.

Armstrong appeared bothered by a back problem and took his hands off the handlebars of his bike to stretch out on several occasions.

Leipheimer moved into third place overall, 40 seconds behind Menchov, while Michael Rogers of Australia fell from third to sixth overall after finishing 14th.

The 12th stage was one of the most grueling time trials in recent grand tours, and took riders about 30 minutes longer to complete than most other races against the clock.

Hugging the spectacular Ligurian coast, the route tilted uphill immediately with a 15.8-kilometer (9.8-mile) climb followed by a nerve-racking descent full of hairpin curves with cliffs heading down to the sea lurking just over the guardrails.

A second climb of 8.8 kilometers (5.5 miles) began shortly after the stage’s midpoint, with another hair-raising descent.

By one estimate, the course contained 600 curves, many of them filled by large crowds.

With the temperature hovering near 30 degrees Celsius (86 F), heat was also a factor.

Olympic time trial champion Fabian Cancellara withdrew from the race before the stage.

Stage 13 on Friday is a mostly flat 176-kilometer (109-mile) route from Lido di Camaiore to Florence.

The race ends May 31 in Rome.