Yousuf drove Corey Collymore to mid-on for four in his second innings in the third Test against the West Indies, taking him to 48 and past Richards' landmark of 1,710 runs, achieved in 1976.
In Pakistan's last Test of the year Yousuf was finally bowled around his legs by part-timer Ramnaresh Sarwan for 124, taking his aggregate for the year to 1,788 runs in 11 Tests, the same number of matches as Richards took for the old record.
Upon reaching the new record, Yousuf raised his bat and looked to the heavens with relief.
"I wasn't competing with Viv Richards, he is a great player, it was only with God's help that I achieved this," Yousuf said after his innings.
The afternoon session brought more records as the Pakistani reached his century in the afternoon session, his second of the match and his ninth of 2006, breaking his own world record.
His fighting 102 in the first innings had already broken the record for hundreds in a 12-month calendar period, previously held by Richards (1976) and Sri Lanka's Aravinda de Silva (1997), with seven each.
Finally, Yousuf, who made his debut against South Africa in 1998, also set a new Pakistan record for most runs in a three-match Test series at 665, erasing the old mark of 583 runs set by former great Zaheer Abbas against India in 1978.
Yousuf started the year with 461 runs in Pakistan's 1-0 win in the three-match home series against old rivals India.
He missed one of the two Tests in Pakistan's away series against Sri Lanka and managed 31 runs in two innings there.
But the middle-order batsman stepped up a gear on the summer England tour, hitting a monumental 202 at Lord's. He scored a masterly 192 at Leeds and followed that up with 128 in the forfeited Oval Test.
His success continued in the current series against the West Indies, starting with a match-winning knock of 192 in the first Test in Lahore. His innings helped Pakistan clinch the match by nine wickets.
Yousuf then salvaged a draw for Pakistan in Multan with his 191, again missing a double century, and held the home team's innings again with his 102 in the first innings of this ongoing Test.