Pakistani opener Imamul Haq was taken to a hospital after a New Zealand fast bowler Lockie Ferguson hit him with a nasty bouncer during the second ODI at Abu Dhabi stadium.
Veteran batsman Ross Taylor top-scored with a laborious 120-ball 86 not out and added 75 for the fifth wicket with Henry Nicholls, who made a snail-paced 33 off 63 balls.
Batting first, New Zealand were restricted at 209 runs in 50 overs and in reply, Pakistan sealed the match with a seven-wicket victory and squared the series 1-1 forcing the final match to be played as a decider.
New Zealand stayed faithful to the same combination which won the first one-day worldwide by 47 runs, also played in Abu Dhabi, while Pakistan brought in Faheem Ashraf for Junaid. "It wasn't enough on that surface".
Sarfraz fell for 13 but Mohammad Hafeez hit the winning boundary to finish with 27 not out. The dazed Imam went off in the ambulance for a concussion check, but that only brought the prodigious Babar Azam to the wicket, and he teamed up with Fakhar Zaman to punish the Black Caps bowlers.
Ferguson, who finished with 3-60, then had another lucky wicket of Shoaib Malik for ten when a ferocious pull deflected off Nicoll's shoulder and was caught at mid-on by Ish Sodhi.
Somerville played 16 first-class matches for New South Wales but requested to be released from the contract earlier this year in order to join Auckland Aces to qualify to play for New Zealand, his country of birth.
In the second over, Shaheen Afridi got an important wicket when Colin Munro skied one in the air and Muhammad Hafeez took a good running catch. Taylor hit three boundaries and a six for his 43rd half century in one-day internationals. The skipper was run out at the non-striker's end by the hand of Afridi. Nicholls was finally bowled in the 38th over by Hasan Ali who finished with 2-59.
Allrounder Faheem Ashraf replaced Junaid Khan in the only change made by Pakistan.