Andy Roddick refocused after losing his cool Tuesday to reach the third round of the Shanghai Masters with a 7-6 (7/3), 7-5 win as top American Mardy Fish crashed out to Australian teen Bernard Tomic.
After Dimitrov broke Roddick in the ninth game of the second set to lead 5-4, the American smashed his bag repeatedly in frustration but immediately broke back to level at 5-5, saving a set point.
Speaking about the incident, Roddick said: "I don't know that I made a first serve that game, you know, so that was frustrating for me. I mean I felt like I was returning pretty well and hitting my forehand pretty well.
"Then all of a sudden I'm not putting a first serve in the court. So I was kind of pissed. I felt like I was getting it backwards a little bit.
"The guy doubles three times and lets you back in, then you kind of donate it right back, that's not normally a recipe to win a match."
But the American said: "There's no such thing as a bad win. I'll keep going in this tournament hopefully."
In the late match at the Qi Zhong stadium, 18-year-old Tomic rallied from a set down to beat fifth seed Fish 4-6, 6-1, 6-4 to join Roddick in the third round.
The 49th-ranked Australian, who lost to ninth-ranked Fish last week at the Japan Open, had only won one match previously against top 10 players but levelled with two breaks in the second set and a single break in the ninth game of the decider earned him the win.
Also in second round action, Swiss 13th seed Stanislas Wawrinka beat America's Donald Young 6-7 (5/7), 7-6 (7/2), 6-2 and France's Gilles Simon, seeded eighth, eased past Spain's Albert Montanes 6-1, 6-1.
Earlier, Germany's Florian Mayer, the 15th seed, beat former world number three David Nalbandian 6-3, 6-4 to reach the third round and seventh seed Nicolas Almagro defeated Spanish compatriot Tommy Robredo 7-5, 6-3.
Tipsarevic won his first ATP title earlier this month at the Malaysian Open but lost in the first round of last week's Japan Open.
Austrian 14th seed Jurgen Melzer, who defeated Rafael Nadal to reach the quarter-finals in Shanghai last year, beat Croatia's Ivan Ljubicic and Alexandr Dolgopolov, seeded 12, beat Lukasz Kubot of Poland.
Source: AFP Global Edition