MILAN, April 16 (Reuters) - A rocket shot from Francesco Totti gave holders AS Roma a 1-0 home win over Catania in their Italian Cup semi-final first leg on Wednesday.In the other first leg, Serie A leaders Inter Milan drew 0-0 at home to Lazio in a dire game on a slippery surface. Lazio played their best side after resting some big guns in Sunday's 1-1 draw with Siena while Inter had a largely second string lineup, with David Suazo and Hernan Crespo their only available strikers due to injury and suspension. The pair combined for the clearest chance when Crespo's effort was well saved before Inter defender Nicolas Burdisso hit the bar. Visitors Lazio were generally better and were only foiled by some last ditch defending and the offside flag. In Rome, Totti blasted in from 30 metres following Mancini's run and pass in the 47th minute to give his side the edge. With the Serie A title race taking priority, Roma coach Luciano Spalletti also picked several reserves but they still dominated and will be frustrated not to have taken a bigger lead into the second leg in Sicily on May 7. Totti, Ludovic Giuly and Cicinho went close to increasing the advantage while league strugglers Catania barely threatened in Walter Zenga's third game in charge. Roma, who have met Inter in the last three finals, are four behind their rivals at the top of Serie A. The Cup final takes place in Rome on May 24.