While contenders such as Florida Governor Ron DeSantis and former United Nations Ambassador Nikki Haley briefly criticised Trump, the latest episode did not appear any likelier to alter the dynamics of a race that Trump has dominated for months.
The candidates spent much of the two-hour event on Wednesday night assailing one another as they strove to emerge as Trump's chief opponent with less than 10 weeks before the first statewide nominating contest in Iowa. They will have one more opportunity on December 6, when a fourth debate will take place in Alabama.
For his part, Trump held a rival event nearby, where he mocked the participants and demanded that the Republican Party stop "wasting time" with "unwatchable" debates.
With only five candidates qualifying for the stage - DeSantis and Haley were joined by US Senator Tim Scott, former New Jersey Governor Chris Christie and entrepreneur Vivek Ramaswamy - it was less chaotic than previous encounters.
But it still had its share of cutting exchanges.
At one point during a discussion about whether to ban TikTok, Ramaswamy noted that Haley's daughter had used the app, prompting Haley to warn him angrily not to mention her daughter again.
"You're just scum," she muttered.
Former UN Ambassador Nikki Haley called businessman Vivek Ramaswamy "scum" during the debate.
Haley, who also served as South Carolina governor, and DeSantis, who has been in a distant second place behind Trump for most of the campaign, had their own clash over which governor had been too welcoming to Chinese investment.
Recent polls have shown the two jockeying for second place in early voting states.
Most of the candidates voiced support for banning TikTok, owned by a Chinese company, over national security concerns - even Ramaswamy, who has defended using the app as a way to connect with young Republican voters.
The debate opened with moderators asking the candidates to explain why they should be the party's standard-bearer rather than Trump, giving them a chance to make their case directly to voters watching at home.
DeSantis criticised Trump for skipping the event, which took place in their shared home state of Florida, and suggested that the party's poor showing in Tuesday's off-year elections should be laid at Trump's feet.
"He said Republicans were gonna get tired of winning," DeSantis said.
"Well, we saw last night - I'm sick of Republicans losing!"
Haley offered a more muted critique.
"Everybody wants to talk about President Trump. I can tell you that I think he was the right president at the right time," she said.
"I don't think he's the right president now."
Trump, 77, has done his best to deny his rivals a direct target, instead focusing on what he expects to be a rematch with Biden, 80, on November 5 next year.
As Wednesday's debate proceeded, the candidates largely avoided attacking Trump, whose hold on Republican voters has proven unshakable even in the face of his multiple indictments.
Instead, they trained their fire on Democratic President Joe Biden, particularly during a lengthy segment on foreign policy and the Israel-Hamas conflict. The Republicans all pledged unconditional support for Israel and assailed Biden's handling of the crisis.
Florida Governor Ron DeSantis clashes with businessman Vivek Ramaswamy as Senator Tim Scott looks on
A day after Democrats and abortion rights groups swept to victory in several state elections, the Republicans sought to formulate a winning message on an issue that has bedevilled the party since the conservative-led Supreme Court last year eliminated a nationwide right to abortion.
The candidates attacked Biden over his stewardship of the economy, arguing that his focus on climate change had slowed growth. Haley and Christie said they would raise the retirement age for Social Security benefits for younger workers to help keep the program solvent, while Scott and DeSantis said they would not do so.
Polls show voters are unhappy with Biden's economic record, despite the fact that inflation has slowed considerably and fears of a recession have faded amid continued economic growth. Biden's approval rating slipped under 40 per cent in the latest Reuters/Ipsos poll, his lowest mark since April.
