Vasek Pospisil poised to make tennis history Friday (UPDATED)

Canadian Vasek Pospisil and American partner Jack Sock had a dream debut as a doubles duo when they won the Wimbledon crown in their first tournament together last month.

Friday in Cincinnati, they're posed to break a record that has stood for at least 30 years.

If Pospisil and Sock defeat No. 2 seeds Alexander Peya of Austria and Bruno Soares of Brazil in the Cincinnati quarter-finals, it will be their 13th consecutive victory.

(UPDATE: Pospisil and Sock squeaked through, 6-2, 5-7, [10-7] to reach the semi-finals, where they would play Daniel Nestor and partner Nenad Zimonjic if the pair wins its quarter-final match later today)

According to the ATP, that would surpass a 12-match debut run by the team of Paul Annacone of the U.S. and Christo van Rensburg of South Africa, who began their partnership by winning 12 straight matches.

The ATP Tour records go back 30 years; no team has done better.

Annacone and van Rensburg won the Sydney tournament on grass in December 1984 (yes, they had tournaments in December back then; the Australian Open was played in November), then the 1985 Lipton championship in Delray Beach (which is now the Sony Open in Miami). They lost in the quarter-finals of an ATP event in Houston. Between Sydney and Delray, both played tournaments with other partners before teaming up successfully and exclusively for many years.

The American Annacone was just 21 at the time – as the American Sock is now, and only turned pro in 1984. Van Rensburg was 22 and a second-year pro.

Pospisil and Sock won six matches to take the title in London and four more to win the tournament in Atlanta three weeks ago. This will be their third match in Cincinnati and, as fate would have it, the third match in which they will face a team they defeated on the road to that inaugural Wimbledon crown.

Here was their draw at the All-England Club:

They beat Rohanna Bopanna and Qureshi 7-5, 6-2 in the first round in Cincy and No. 5 seeds Paes and Stepanek 6-1, 4-6, [10-8] in the second round.

Peya and Soares are the No. 2 seeds, as they were at Wimbledon.

How did Annacone and van Rensburg work out? They won eight tournaments together including the Australian Open title in 1985, which was played on grass, and reached eight other finals.

Annacone, a pure serve-and-volleyer and chip-and-charger in the best old-school tradition, reached No. 12 in singles and No. 3 in doubles during his career. After his playing days, he became a respected coach whose pupils so far have included Pete Sampras, Roger Federer and, more recently, Sloane Stephens.

Van Rensburg reached No. 19 in singles and No. 5 in doubles, with two singles and 20 doubles titles to his credit.

Pospisil and Sock no doubt would be quite happy with those careers.

In a full-circle sort of thing, van Rensburg and partner David Wheaton handed American doubles legends Bob and Mike Bryan their first career defeat on the ATP Tour, 6-4, 6-7, 7-6 in the second round of a tournament in Atlanta ... in 1996. Van Rensburg was an "old man" of 33; the Bryans had turned 18 that very week and were ranked 1,210 in the world.

The Bryans, who were in college and only turned pro in 1998, began their careers on the circuit with a 3-14 record before going down to the Futures/Challengers level for a few tournaments and retooling.

Eighteen years later, at 36, the Bryans remain the undisputed No. 1 team in the game and are closing in on 100 career doubles titles. They could be Pospisil and Sock's opponents in the Cincinnati final, if both teams make it.

Where does Canadian tennis legend Daniel Nestor fit in?

He and longtime former partner Mark Knowles began their partnership late in 1994 by winning an ATP Tour event in Bógota, Colombia. They then won a Challenger in New Zealand to start the 1995 season before reaching the Australian Open final. So their debut streak was nine matches - 13 if you count the Challenger win.

(Tip of the Yahoo hat to Open Court Twitter follower Paul Fairie of Calgary, who asked the question).