Ambati Rayudu cracked an unbeaten 29-ball 55 as Mumbai Indians put up a sterling all-round performance to virtually seal a semifinals berth beating champion Deccan Chargers by 63 runs in their Indian Premier League match here Saturday. Opting to bat, Mumbai Indians piled up a challenging 178-5, thanks to Rayudu and youngster Saurabh Tiwary who made a 44 off 35 balls. The host then bowled out the Adam Gilchrist-led side for 115 in 18.2 overs. Score: Mumbai Indians 178-5 in 20 overs (Ambati Rayudu 55 not out; Pragyan Ojha 3-26). Deccan Chargers 115 all out in 18.2 overs (Andrew Symonds 21; Zaheer Khan 2-10, Harbhajan Singh 2-16). In the day's first match Chennai Super Kings beat Rajasthan Royals by 23 runs in Chennai. Chennai Super Kings, led by M. Vijay, pulverized the Rajasthan Royals bowling and scored 246-5 batting first. From 91-2 after 10 overs, Chennai ransacked 155 in the final 10, and 76 in the last five, with Vijay and Albie Morkel setting a record for the tournament's highest partnership. Chennai then restricted Rajasthan to 223-5 in the allotted overs. Scores: Chennai 246-5 in 20 overs (Murali Vijay 127, Albie Morkel 62, Shane Watson 2-47) Rajasthan Royals 223-5 in 20 overs (Naman Ojha 94 not out, Shane Watson 60; Doug Bollinger 2