Captain Ajit Agarkar and wicketkeeper Aditya Tare ground a pedestrian Services attack to score patient centuries as 39-time champions Mumbai ended the second day's play in the Ranji Trophy semi-final on 380 for 6 in 143 overs.
The Agarkar-Tare pair added 211 runs in an unbroken seventh-wicket stand as the home team's bowlers failed to take a wicket in the 65 overs bowled on Thursday.
At stumps, Agarkar was unbeaten on 113 (14x4) and Tare on 108 (16x4).
The duo eschewed risks, slowly and surely going about their task of trying to bat the minnows out of the game.
Services' medium pacers Nishan Singh, Suraj Yadav and Shadab Nazar, who bowled well under overcast conditions on Wednesday, paid dearly for their inexperience at this level as they failed to make the batsmen play in the first session.
Gritty Tare and the seasoned Agarkar did leave a lot of deliveries but once the bowlers were frustrated, they got into the groove and played some lovely shots all round the wicket.
While Tare faced 324 balls, his captain got his runs off 237.
On a low and slow track, the absence of a quality spinner was badly felt by Services.
Left-arm spinner Abhishek Sinha might have got Sachin Tendulkar's wicket on the first day but he is certainly not a top notch spinner even in the domestic circuit.
Agarkar was the first to reach fifty, off 109 balls, while Tare needed 198 deliveries to get to the landmark.
Their approach wasn't pleasing to the eye, but effective nonetheless.
Tare got his second century of the season and his first-class career when he steered one past first and second slip off Nakul Verma. He faced 297 balls and hit 16 boundaries in the process.
That he batted close to 414 minutes for a century was testimony to his patience. He scored 222 against Saurashtra at Rajkot earlier this season.
Agarkar, whose most memorable ton till date was at Lord's back in 2002, pushed one from Sinha towards mid-on to complete his fourth three-figure score in first-class cricket.
He skipper faced 216 balls in 294 minutes, hitting 12 fours.
Mumbai: 380 for 6 in 143 overs (Ajit Agarkar 113 batting, Aditya Tare 108 batting, Sachin Tendulkar 56, Abhishek Nayar 70) vs Services.