Alex de Minaur and Katie Boulter in 'terrible' twist as Novak Djokovic sledge burns Nick Kyrgios

Katie Boulter has admitted it will be "terrible" cheering against fiance Alex de Minaur after handing Australia a huge boost in the United Cup on Monday night. And Nick Kyrgios made a successful return to tennis alongside Novak Djokovic at the Brisbane International.

Boulter's Great Britain team defeated Argentina 2-1, handing her fiance and the Aussies a big chance to make the quarter-finals. Boulter and Charles Broom sealed victory for Team GB with a 7-6 (7-4) 7-5 win over Maria Carle and Tomas Etcheverry in the mixed doubles at Ken Rosewall Arena in Sydney.

Boulter had earlier won the women's singles rubber with a 6-2 6-3 win against Nadia Podoroska, and continued her impressive form in the doubles. It means Australia can still progress to the quarters after their loss to Argentina in the opening tie.

De Minaur and the Aussies would need to beat his fiancee's GB team on Wednesday to progress to the knockout stage. "We did them (Australia) a favour today giving them a 2-1 win, so they can thank us later for that," Boulter said. "We've got everything to play for. I'm going to come in all blazing."

Boulter is unlikely to come face-to-face with de Minaur in the mixed doubles on Wednesday, with Matt Ebden and Ellen Perez the likely picks for Australia. And she admitted it won't be easy cheering for her teammates to beat her fiance.

"I don't know about having a little match against him," Boulter said. "I think that's going to be terrible and a bit of a popcorn match." It marks the second year in a row that Boulter and de Minaur have clashed on rival teams in the United Cup. And it comes after the superstar couple announced their engagement earlier this month after four years together.

Novak Djokovic's cheeky sledge for Nick Kyrgios

Meanwhile, Kyrgios teamed up with Djokovic to beat Alexander Erler and Andreas Mies 6-4 6-7 (4-7) 10-8 in the doubles in Brisbane on Monday night. Kyrgios didn't show any signs of rust while playing just his second tour-level match in two-and-a-half years, producing a strong serving display and moving freely.

Djokovic was full of praise for Kyrgios, but burned his Aussie friend with a cheeky sledge during their on-court interview. When Kyrgios said he was trying to be as "professional" as possible, Djokovic cracked back: “The highlight of this interview so far… his sentence, ‘I’m trying to be professional.’ I love it. I love it.”

The 24-time grand slam champion was so impressed by what he saw that he reckons Kyrgios can trouble anyone at the Australian Open - even the world's best. "Hopefully Nick can stay healthy because, with this game, he can beat anybody on any surface, so it's great and exciting news for all the tennis world seeing him back on the court," Djokovic said. "It's hopefully a great start of the season for both of us and we can keep it going in singles and see how far we can go."

Djokovic was back in action after skipping the ATP Finals at the end of the season. He won gold at the Paris Olympics in 2024, but failed to win a single grand slam for the first time in seven years. However the 10-time Australian Open champion is adamant he can claim an unprecedented 25th grand slam crown in 2025.

"I feel great, cannot ask for a better start of the season sharing the court with Nick for the first time," said the Serb. "Winning the match, getting a little bit of a feel for for the court. I look forward to obviously singles, a completely different, different match, different feeling on the court I'm going to have to do - much more running, but I'm ready for it."

with AAP