ROME, Feb 4 (Reuters) - AS Roma maintained their formidable form on Thursday with a 2-0 home win over Udinese in the first leg of their Italian Cup semi-final.

Mirko Vucinic latched on to a pass from deep by Daniele De

Rossi before slotting the ball into the corner and Philippe

Mexes headed home in the first half to put the hosts in command

of the tie.

The victory stretched Roma's unbeaten run in all

competitions to 18 games, having moved level on points with

second-placed AC Milan in Serie A on Sunday with a 2-1 win over

Siena.

On Thursday, they played some neat one-touch football in the

opening phase with captain Francesco Totti back from injury

along with fellow striker Vucinic, who gave them a 12th-minute

lead with the help of some distracted defending.

Udinese, who are fourth-from-bottom in Serie A, had more

possession as the first half wore on but created few chances.

French defender Mexes beat their back-line to a David

Pizarro free-kick to extend Roma's lead in the 40th.

The home side cruised in the second half and Udinese's

failure to make an impression on the score-sheet leaves them

facing an uphill task in the return leg, which is scheduled to

take place in April.

Serie A leaders Inter Milan beat Fiorentina 1-0 at the San

Siro on Wednesday in the first leg of the other semi.