The phrase "a last round" is correct and usable in written English.
It can be used in contexts where you are referring to a final opportunity or instance of something, often in social or competitive settings.
Example: "Before we call it a night, let's have a last round of drinks to celebrate our success."
Alternatives: "a final round" or "one last round".
They are planning a last round of presidential travel that will be heavily draped in symbolism.
Standing over the supine alien, Stiller fired a last round, and then, after a beat, Vaughn fired a last round, and then Stiller fired, and Vaughn fired, and Stiller, after a long pause, fired a final last round.
"I offer you a completely new approach," Mr. Kenyatta said during a last round of campaigning this week.
So the great carnival ended, with a last round of applause for Lionel Messi's 91st goal of 2012.
After a last round of tea, the miners curled up in their blankets, and I walked outside to my tent.
Consulted by the White House during a last round of debate, the General also asked for a deployment of the greatest possible size.
Win, and the likely prize is a last-round qualification showdown at Ravenhill with the big French team Biarritz.
The Olympic champion Edwards jumped 17.26m to claim this title for the fifth time, overcoming a rib injury and a last-round scare when Greece's Christos Meletoglou produced an effort of 17.19m.
Reed started two games this season for the Jets and played in several others, but he says that he has not yet overcome the stigma of being a last-round pick.
Wie had a last-round 67 to finish 14 under, the first time since the Evian Masters in July 2006 that she completed an event under par — a streak of 13 events that included seven missed cuts.
The women's long jump went to Kirsten Bolm of Brigham Young, who edged Houston's Jenny Adams by three-quarters of an inch with a last-round effort of 21-6.
