All-rounder Abhishek Nayar cracked an unbeaten 111 after coming into the Mumbai side following an injury lay-off to help the holders recover from a difficult pre-lunch period on the opening day of their Ranji Trophy semifinal against Delhi in Mumbai on Sunday.
Reduced to 86 for three on a bouncy pitch, Mumbai staged a remarkable recovery, thanks mainly to Nayar's gritty display and his two significant partnerships with Onkar Khanvilkar (70) and Ajit Agarkar (57 not out).
At stumps, the 38-time champions were at a sound 329 for four in 83 overs, which looked a distant dream when they had lost their top three batsmen, including skipper Wasim Jaffer, by the 25th over in an extended first session.
Nayar added 145 runs for the fourth wicket with another left-handed batsman Khanvilkar off 221 balls to steady the rocking boat on either side of lunch and then put on 98 runs during a breezy, unbroken fifth-wicket partnership with the free-stroking Agarkar to consolidate the innings.
Towards close Nayar, who missed Mumbai's last three games due to a hand injury, suffered cramps in the right hand but his partnership with Agarkar, which produced a near-century stand in only 105 minutes, has swung the match towards the hosts.
But the morning session, after Mumbai captain Jaffer won the toss and elected to bat at Brabounrne Stadium, belonged to the visiting team with paceman Ishant Sharma breathing fire from one end with pace and lift.
Ishant sent back Mumbai's mainstay Jaffer (7) cheaply, who chose to open the innings with Sahil Kukreja, by trapping the right-handed batsman leg before when the home team skipper tried to flick to leg.
Ishant came back for his second spell and sent another top Mumbai batsman Ajinkya Rahane's (29) off stump reeling, as he too tried injudiciously to play across the line, to reduce the hosts to a worrisome 86 for three.
In between these two dismissals Parwinder Awana made a ball climb up from good length and had Kukreja (29) caught behind by Puneet Bisht to make Mumbai 56 for two in the 18th over.
But the left-handed pair of Nayar and Khanvilkar weathered the storm with some judicious batting to take Mumbai to 100 without further loss at lunch.
Sharma was off the field soon for 20 minutes after resumption and his absence saw the fourth wicket pair slowly and steadily growing in confidence.
Nayar, subdued in the beginning, started attacking the bowling and slammed off spinner Mithun Manhas for sixes over the straight field in successive balls to break free of the shackles and from that stage Mumbai held sway.
Mumbai: 329 for four in 83 overs (A Nayar 111n.o., O Khanvilkar 70; I Sharma 2/48).
Pandey, Pawan propel Karnataka
Bangalore: Half centuries from Manish Pandey (66) and K B Pawan (52) helped Karnataka make a steady 255 for four on the opening day of their Ranji Trophy semi-final against Uttar Pradesh at the M Chinnaswamy stadium.
A composed Rahul Dravid (37 not out) and R Vinay Kumar (7 not out) were at the crease, promising to consolidate hosts' position on a hurriedly prepared slow and low deck.
Opting to bat, Karnataka began on a sedate note with Robin Uthappa (32) and K B Pawan producing a 42-run stand for the first wicket.
Uthappa was in good nick before committing hara kiri, unsuccessfully attempting to paddle sweep left arm spinner Praveen Gupta.
Umpire Sanjay Hazare had no hesitation whatsoever in adjudging Uthappa leg before the wicket.
Pawan, a prolific run-getter this season, frustrated Uttar Pradesh with his dour defence in the company of a confidence-personified Ganesh Satish (49).
They were in complete command before left-arm medium pacer R P Singh produced two wickets in five balls, having Pawan and Satish snared behind the wickets by Amir Khan.
But Dravid, in imperious form this Ranji season, and Manish Pandey thwarted the sudden Uttar Pradesh surge, raising 108 runs for the fourth wicket.
Pandey was the dominant partner, punching through the off and driving through the on with élan. His stroke play and timing was a treat to watch, as he caressed the cherry with effortless ease to the pickets.
With his bowlers unable to find the breakthrough, Mohammad Kaif summoned the second new ball close to the end of first day's play.
It paid dividend as Pandey, who had taken his season's aggregate to a whopping 724 runs, waved his willow at a distant Praveen Kumar delivery for Kaif to complete an overhead catch at the second slip.
Karnataka: 255 for four in 95 overs (M Pandey 66, K Pawan 52; RP Singh 2/53).