Baroni replaces Giampaolo at Siena
The Tuscan club suffered their seventh defeat of the campaign in Wednesday's 2-1 reverse at Bologna and have managed just one win. They host struggling Lazio on Sunday.
"Siena announce that we have dismissed Marco Giampaolo (pictured) and his staff. The team has been entrusted to Marco Baroni, who will direct his first training session this morning," a statement said on the official website.
After gaining a first-ever promotion to Serie A in 2003, Siena continually staved off the threat of relegation and were becoming a steady mid-table side.
Such was their form last season that media reports said Giampaolo was even in the running for the Juventus job before Ciro Ferrara replaced Claudio Ranieri in May.
Giampaolo, the sixth managerial sacking in Serie A this term after just 10 games, threatened to leave in the close season after being disillusioned by the lack of buys and the departure of top players such as Houssine Kharja.