His victory over Verdasco breaks an 0-3 career losing streak against the Spaniard, which stretches back to the first round of the US Open in 2004, when Andreev fell to Verdasco in five sets.
The Russian's next test will be his toughest yet here at the Open, as he will face No. 2 seed Roger Federer, who has so far sailed through his first three rounds without dropping a set.
Andreev had little trouble getting past Verdasco, who showed up with an uncharacteristically inconsistent game and committed a crippling 33 unforced errors. The key to the No. 23-seeded Russian's win was that he produced a much cleaner game with only 10 unforced errors.
The 25-year-old Russian registered at 95 percent on his first-serve win percentage, a stat that was largely due to the fact that Verdasco could not cleanly connect with Andreev's powerful serves and put them in play.
Andreev started the match off strong and took an early break of serve on Verdasco's errors for a 3-1 lead. Another break in the seventh game on a netted Verdasco forehand set Andreev up to serve for the first set, which he did successfully on yet another serve return dumped in the net by Verdasco.
Verdasco held his own through the first half of the second set, until a low, driving passing shot slipped under the approaching Spaniard's racquet for another break of serve and a 3-2 lead for Andreev. Though Verdasco produced a few forehand winners of his own, Andreev's one break of serve was all he needed to take a two-sets-to-love lead.
The third set was almost a mirror image of the first, as Andreev broke Verdasco again in the third game when the Spaniard netted a forehand volley. The left-handed Verdasco never had a break point on Andreev the entire match, but the crowd in Grandstand got behind the Spaniard after a few questionable calls to try and lift his spirits and help him get back in the match mentally.
Andreev had triple match point on Verdasco's serve at 5-3, but Verdasco took advantage of consecutive Andreev errors to hold and force the Russian to serve out the match. Andreev closed it out by holding at love on a netted Verdasco forehand.
