Tour de France holder Alberto Contador made his move in the Giro d'Italia's first individual time trial on Tuesday.
Contador, one of the pre-race favourites, came in second, eight seconds behind winner Marzio Bruseghin.
Another fancied rider, Contador's team mate Andreas Kloden, was 12 seconds behind the Spanish ace.
The leading riders - including Giro holder Danilo Di Luca, past two-time winners Paolo Savoldelli and Gilberto Simoni, Tour of Spain winner Denis Menchov of Russia and Italy's up-and-coming Riccardo Ricco' - are expected to launch their first major bids for the lead during a triple-whammy Alpine trek from Saturday to Monday, ending with the race's second time trial.
Four days later, the final challenges should come during a two-day Dolomite ordeal - including the highest point on the Giro - on stages 19 and 20.
This should settle things but, unlike virtually every previous edition, the 21st and last stage is not the usual leisurely spumante-popping run-in to Milan.
Instead, a third time trial might give the top 'chronomen' a chance to get back into the reckoning.
Here are the overall standings after Tuesday's 10th stage from Pesaro to Urbino:
1. Giovanni Visconti (ITA) 43h12:02.
2. Matthias Russ (GER) 3:31 behind
3. Gabriele Bosisio (ITA) 5:50
4. Alberto Contador (SPA) 6:59
5. Marzio Bruseghin (ITA) 7:52
6. Andreas Kloeden (GER) 7:54
7. Vincenzo Nibali (ITA) 8:04
8. Paolo Savoldelli (ITA) 8:09
9. Riccardo Ricco' (ITA) 8:32
10. Danilo Di Luca (ITA) 8:33
11. Gustav Larsson (SWE) 8:33
12. Denis Menchov (RUS) 8:57
13. Gilberto Simoni (ITA) 9:10
14. Levi Leipheimer (USA) 9:10
15. Franco Pellizotti(ITA) 9:15
16. Juergen Van den Broeck (BEL) 9:43
17. Emanuele Sella (ITA) 9:44
18. Christian Vande Velde (USA) 9:46
19. Evgueni Petrov (RUS) 9:48
20. Marco Pinotti (ITA) 9:56
21. Felix Cardenas (COL) 10:14
22. Leonardo Piepoli (ITA) 10:16
...
36. Paolo Bettini (ITA) 13:00
81. Erik Zabel (GER) 39:20
94. David Millar (GBR) 44:53
155. Robbie McEwen (AUS) 1h21:02
Wednesday's 199km 11th stage runs from Urbania to Cesena, with a 29km hilly stretch near the end.
Thursday and Friday allow the main contenders to rest on two made-for-sprinters ambles from Romagna to Veneto, ahead of the three-day climbers' duels in the northeastern Alps.
