Elia Viviani of Italy bolted to the front in the final yards to win Stage 4 of the 2011 USA Pro Cycling Challenge earlier today, while Team RadioShack's American Levi Leipheimer maintained his overall lead.

Viviani, 22, a second-year pro who rides for the Italian Liquigas-Cannondale team, used a centerline sprint to complete the 82.3-mile Avon to Steamboat Springs road race in 02 hours, 58 minutes, 14 seconds.

Leipheimer regained the overall lead Thursday when he claimed his second stage of the race in the 10-mile, uphill Vail individual time trial.

Leipheimer leads Christian Vande Velde of Team Garmin-Cervélo by 11 seconds.

The top 10 overall riders in the seven-day race all finished in the main field in the fourth stage and there were no changes at the top of the overall standings.