The Iranian tallied seven points to tie with IM Shen Yang of China, but had a better tie-break
of seven wins against five for the Chinese silver medallist.
With Surrey 5-3 up, the Warwickshire Thirds Soumeya Anane and Alannah Griffin upset the second pair Natasha Starling and Laura Peterzan with a battling 13-11 victory on the Championship tie-break
Djokovic forged two match points after leading 6-4, but following a memorable rally between the pair and stunning back-hand return from Del Potro, the Argentine crowned the finest of all comebacks by winning the tie-break
and forcing a deciding set.
The Guernsey player then came from 3-0 down to win the tie-break
9-7, in the process saving set points for the second and third times.
That meant yet another match tie-break
for the British pair, Kas and Lisicki matching them point for point.
The Frenchman hit back to take the third, again on a tie-break
, but his hard work was wasted at the start of the fourth as Djokovic stormed into a 2-0 lead after breaking his opponent to love.
And the delay might have been a blessing in disguise for the Spaniard who stumbled to the floor on the ninth point of the tie-break
and took longer than usual to get up.
Murray recovered from a break down to win the first set of his thirdround match with Wawrinka on a tie-break
After losing the tie-break
7-3, Dimitrov capitulated and allowed his opponent to take a 5-0 lead in the second set, which Amritaj won 6-1.
The second seed took a topsyturvy first set on a tie-break
and battled back from a break down to seal a meeting with Frenchman Marc Gicquel in the last eight.
Federer, who will be gunning for his third straight Wimbledon title this summer, won an epic second-set tie-break
to prevail 6-4, 7-6 (11/9) over Haas.
victory means he has now beaten Roddick twice in three meetings this year.